James Emery at Backscatter has published a review and a field video of three Nauticam wet lenses that mount on the same macro port: the MFO-1, the SMC-3, and the MFO-3II.

All three are 67mm lenses, so on a flip holder you can move among them on one dive without changing the camera lens. They do different jobs. The MFO-1 is the everyday optic: a little magnification, and a shorter focus range so autofocus stops hunting the water column. The SMC-3 is the super-macro lens, about 2.3:1, for the smallest subjects. The MFO-3II opens a 90mm, 100mm, or 105mm toward a 60mm view, which is the one for larger subjects and blackwater.

Read the Full review · Watch the video

Curious about the new Sony FE 8-14mm F3.5 Fisheye G?

One of our community members, @Simon Pierce had early access to the newly announced Sony FE 8-14mm F3.5 Fisheye G

Visit the forum to explore a detailed pre-release breakdown covering underwater housing setups, size comparisons, and downloadable sample shots.

Image Credit: Simon Pierce

There has been discussion recently about the new DJI Osmo Pocket 4P. DJI claims up to 17 stops of dynamic range on its new 1-inch sensor, and comparisons with cinema cameras like the ARRI Alexa quickly surfaced online. Looking at the numbers, it might seem plausible, but visually the situation is different.

Spoiler: no, it is not a micro Alexa.

PetaPixel confirmed after testing it that LOFIC improves both highlight retention and shadow cleanliness, though they noted their empirical tests did not reach the full 17 claimed stops. Even if the Pocket handles backlighting very well for its size, it does not output the same image. First, 1-inch pixels physically generate more noise in deep shadows compared to the massive photosites of a Super35 or 35mm sensor. Second, it lacks the smooth highlight roll-off of Arri; on the compact sensor, the clipping to pure white is inevitably harsher. Furthermore, the DJI data ends up in a 10-bit MP4 using D-Log 2, going through a processing pipeline far different from the RAW workflows of the Alexa family. It remains a notable achievement to have this exposure latitude on a pocket camera, which is due to the LOFIC hardware.

What exactly is LOFIC technology?

To understand this solution, we need to look into how a sensor is built. Simply put, each image pixel corresponds to a photodiode, which is the physical silicon element that receives light, photons, and converts it into electrical charge, electrons.

Imagine this photodiode as a small bucket collecting light. This bucket has a maximum physical volume, which in technical terms is called Full-Well Capacity.

In standard sensors, if we adjust the exposure to properly read details in the shadows, the buckets located in the very bright areas of the frame, such as backlit water surfaces, fill up in a fraction of a second. Once full, any continuing light overflows and is lost. The sensor converter then registers a total saturation signal, leaving us with an unrecoverable white area in post-production.

This is where LOFIC, Lateral Overflow Integration Capacitor, comes into play. For every single pixel, alongside the photodiode and standard circuitry, engineers added an expansion tank of sorts: a dedicated capacitor.

The primary photodiode is kept sensitive to capture a clean signal in shadows and midtones. However, when the light is strong enough to saturate this first stage, the excess electrical charge is managed and stored in the lateral capacitor, which has a larger storage capacity.

When generating the image, the sensor architecture can simultaneously use the signal from the photodiode and the charge stored in the LOFIC capacitor. Merging this information results in a frame with higher dynamic range, physically generated at the exact same moment, single-exposure HDR, and without the flaws of software HDR.

Why it makes a difference for video

This technology changes little for photography. If there is too much contrast, we use bracketing or recover the shadows from a solid RAW file. In video, however, classic HDR, which merges frames with different exposures offset in time, has always been problematic. If we film fish, waves, or anything moving quickly, the merging of frames inevitably creates trails and ghosting artifacts. LOFIC solves this issue by capturing the entire dynamic range at the exact same physical instant. You can shoot at 50 or 60 fps and keep the action perfectly sharp.

The current obstacle for larger formats involves architectural complexity and power optimization. Bringing this system to larger surfaces requires circuitry capable of handling a vastly superior amount of data and bandwidth, all while limiting power consumption and the resulting thermal dissipation.

Current availability and future developments for M43 and smartphones

It is not surprising that this technological advancement comes from the smartphone market: the global smartphone market in 2025 totaled 1.25 billion units sold, while the entire photography sector, including compacts and mirrorless cameras, did not even reach 10 million.

Some manufacturers have already taken action. Xiaomi adopted a LOFIC architecture, utilizing the OmniVision OV50X or Light Fusion 1050L sensor, on the main 1-inch camera of its Xiaomi 17 Ultra. OmniVision itself is among the most active companies on this front, integrating TheiaCel technology, based on LOFIC, to provide a concrete response to the needs of the automotive sector, where autonomous driving sensors require flawless reading of shadows and highlights in all conditions, leaving no margin for error.

Outside the smartphone world, the Osmo Pocket 4P is effectively the first video camera to adopt it. Towards the end of the year, we will see it on an increasing number of high-end phones thanks to the new Sony Lytia L910 sensor, which has already entered production: roughly 50 effective megapixels on a 1/1.28 type chip, 100 dB of single-exposure dynamic range, about 16.6 stops, and 4K60 HDR video. A module that Sony officially presents by emphasizing the low-power optimization of its circuitry.

Final Thoughts

The transition that concerns us most directly, however, is the arrival on mirrorless cameras. Currently, the physical limit achieved and marketed with LOFIC architecture is the 1-inch format. However, industry roadmaps and component suppliers indicate that smartphone manufacturers aim to cross this barrier to reach the Micro Four Thirds format in the coming years. That format will be the natural bridge to our dedicated cameras as soon as the systems to manage the large volume of data and thermal dissipation on the camera bodies are finalized.

Having recently written about installing the o-Turtle trigger into a Nauticam housing, I’ve now had a go with a UWT internal trigger for the Nauticam NA-OM1 housing. UWT describes it as the 11072-22-HSS TTL-Converter for NAUTICAM for OLYMPUS/ OM SYSTEM.

The UWT trigger arrives in a bubble-wrap envelope in a small cardboard box. No frills functional. It consists of a small electronics board with two LEDs and a cable leading to a hot shoe connector. The manual explains that strobes are selected through a small click-dial (just visible in the bottom right of the picture). That is the whole of the setup. There is no battery with power being drawn, I guess, from the camera. The trigger provides Manual, TTL and, with the right strobes, HSS initiation.

The manual explains that, no surprise, the board is fixed to the housing bulkhead so that the two LEDs shine through the housing fibre optic ports. Unlike other UWT boards (eg for Subal - which uses two screws), the fastening is achieved by two strips of double-sided tape which are pre-installed on the trigger board. “Simply” peel back the tape, and push into place.

Full details are here:

https://uwtechnics.com/product/11072-22-hss-ttl-converter-for-olympus-for-nauticam-underwater-housings-na-om1-em1-iii-em10-iv-em1x-em5-ii-em-5-iii-om1/

Installation seemed simple, but having experienced initial placement failure with the o-Turtle, I was more than slightly nervous about sticking the UWT board in place. After hours of thought, I used a very soft pencil (3B) to draw two straight lines on the inside of the housing which ran vertically through the LED ports; and single a horizontal line across the LED ports. The lines were longer than the size of the board so that they could be seen even with the board in place. The lines meant the alignment of the LEDs on the bulkhead could be checked even when the electronic board hid them.

With the camera installed in the housing and strobes plugged in to front of the bulkheads, I pushed the UWT connector on to the camera hot shoe and watched how the cable allowed the electronics board to drop onto the bulkhead. Moving the board around slightly it was still possible to see the guide marks. Holding the board with a finger in what seemed the correct position, the shutter trigger was pulled - and bingo - the strobes fired. Yay!

Couple more trial goes followed just to make sure.  Then removing the protective film from the sticky pads on the board and, again, using the pencil marks for alignment, I secured the board into place. Wiping the beads of sweat off my forehead, I pulled the trigger a few times and my Retras happily flashed away.

Playing around, Manual and TTL were a breeze. HSS took a little while to discover the settings needed on the OM-1ii but that was soon going too.

Using a UWT trigger on a Nikon/Subal system for over a decade proved very reliable. Any problems and Pavel, who is Mr UWT, is a tremendous source of help. Now based in Taiwan, UWT triggers are available by mail order or from the usual underwater photography dealers.

Having bought a Nauticam housing and OM System OM-1ii recently as the base of my new underwater camera setup, I needed an LED trigger to fire the strobes.

Although I havn’t used TTL underwater for many years, I did want HSS as I often include the sunball when shooting wide-angle.  This usually requires high shutter speed to avoid exposure burn outs.

HSS options for an OM trigger seemed to boil down to the Turtle or UWT. The Nauticam flash trigger, although an attractive option, doesn’t provide HSS.

I’ve been a fan of UWT for many years as it proved highly reliable on my late-lamented Subal/Nikon system and the man behind UWT, Pavel, is very helpful if the need arises.

The o-Turtle 3 (Manual /HSS and TTL/HSS models are available) has the slight advantage of being produced in the EU (Hungary) and the man behind that product, Balazs, is also super helpful.  Both Pavel and Balazs are well-known to Waterpixels and their posts much-appreciated.

The o-Turtle comes packed in a very neat travel case which contains all the parts: the electronics box, a small wired connector with two LEDs which push into two small circular plastic discs,  and double-sided circular tape patches to fasten the plastic disks onto the optical bulkheads. An extra battery is also provided plus a USB-C to C cable and, nice touch, a USB-C to USB-A adaptor. All in all, a very neat package.

Full details are here: https://www.trt-electronics.com/shop/o-turtle-3-manual-mobie-trigger-with-99-cd-leds/69/

Installation is relatively straight-forward. Download the relevant Turtle app  from the usual App stores, connect the electronics box to your PC or Mac, choose the strobes you plan to use - and the app uploads the relevant firmware. Job done. See the link for more details.

https://www.trt-electronics.com/content/media/docs/o-turtle-3-smart-user-manual.pdf

Fitting the system into the housing is pretty easy too. Turtle have a video on YouTube to help if necessary. Slide the electronics box onto the camera hotshoe, stick the sticky disks over the strobe bulkheads, insert the LEDs, plug them into the electronics box… and pretty much, voila.

I would suggest a small note of caution with one element of the installation which the video does not highlight. Many housing interiors are black, as are the Turtle LED plastic mounting disks, as is the double-sided sticky tape with which you stick the plastic disks over the strobe bulkheads. Not surprisingly alignment is critical and it’s not so easy amid all that blackness. I have to admit my first attempt resulted in the strobes not getting sufficient light to fire. Doh.

What worked for me was:

1. Remove the LEDs from the plastic disks

2. Fix one of the sticky patches to the bulkhead side of a plastic disk.

3. Lie the housing bulkhead-side down on top of a smartphone torch with the light shining through the bulkhead. This makes aligning the plastic disc MUCH easier. Stick the sticky patch in place.

4. Remove the sticky protector cover from the bulkhead-side of the sticky patch, centre the plastic disk over the bulkhead using the light from the torch to get an accurate position and push into place

5. Then insert the LED into the back of the plastic disk.

6. And repeat for the second LED/disk.

Once the disks were in the right place (!), the strobes fired like a charm. Phew.

I thought some readers might find this helpful…….

Some time back, I wrote an article about creating your own fibre optic cables: a quick, easy, inexpensive and very satisfying process. In case you missed it it, a link to the piece is here.

https://waterpixels.net/articles/articles_technique/diy-fibre-optic-cables-easy-r32/

Now, many months on, a couple of additional suggestions:

BURPING

On entering the water and descending the plugs at both ends of the cables often need burping. Tiny air bubbles seem to be able to block fibre optic light transmission. Easy to resolve of course: simply remove and replace the plugs at the camera bulkhead and strobe ends of the cable.

Worth checking especially before setting up for that crucial, once in a lifetime image.

DAMAGING THE CABLES

On a recent long dive trip in Raja Ampat, my system was being hauled in and out of RIBs with the strobe arms being moved and folded sometimes by me, sometimes by the boat crew.

At some stage one of the fibre optic cables gained a small “crimp” which resulted in the attached strobe not firing consistently. Annoying of course although easy to replace the cable.

This got me thinking about a way to protect the cables. For my next trip I used some cheap garden micro-watering system hose tubing to provide a protected route for the cables from the housing bulkheads to the strobes. Cost was a few cents.

I found it slightly better to cut the tubing slightly shorter than the fibre cables as this allowed for easier curves at each end.

The tubing is held against the float arms using short loops of bungee cord.

I found it worked best to push the fibre cables into the strobe plugs only on descent or at depth. This allowed for burping and avoided any strain on the connections whilst handling during entry.

In general I’ve found it better not to have fixed connections at both ends of the fibre cable. If one end can pull loose when strained, (best I've found is the strobe end) this avoids breaks and overstrains especially during transportation or in rinse tanks (avoid them at all costs!). If stretched or tugged the cable will simply pop out of the strobe end bush. No damage results and the cable is easy to push back in.

The first photograph shows the fibre optic cable and the garden hose tubing; next one with the fibre pushed through the tubing; then "hung" on the strobe arms; and finally the loops to hold the tubing and cable in place.

A few months ago in November, Scubalamp showed a new "small strobe". I like small strobes and wanted one, but they have never appeared on the Scubalamp website. However there is a Fotocore GTM (the same ones in the Scubalamp posts that are available. I bought two of them, and last Saturday, I got to try them out here in Los Angeles. The strobe is a bit larger than the AOI RC strobes, and a bit smaller than the YS D3 Duo.

The strobe is machined aluminum and appears to be very solidly built if a bit heavy (815 g without the 2 x 18650 batteries). The strobe has 7 power levels that are shown on a nice little LED screen on the back. The key advantage to the GTM is that it has beautiful light since it uses a circular flashtube. One peculiarity of the strobe is that it uses only flattop 18650 batteries that are both hard to find and expensive. I have boxes of 18650 button tops, but no joy in these strobes.

To test them out, we went out diving to our local favorite spot off of Palos Verdes not far from LAX. I was shooting an OM-1 camera in an AOI housing with the 2 GTM strobes an a Leica/Panasonic 45 mm macro lens. The AOI has a built in LED trigger that never missed a shot with the strobes, I was using home-made fiber cables using the 613 core fibers.

The Balonophyllia is a solitary stony cup coral, its main claim to fame is that in the colder months (it is always cold at PV, typically 50F, 10C) it can in fact sequester dissolved organic carbon from the seawater directly. Hopefully it can teach its warm water cousins the same trick. If California had a state nudibranchs it would likely be the Spanish Shawl

These guy are everywhere and are quite beautiful. Interestingly the orange/blue/red and purple colors are all from the same molecule but with different arrangements of some elements.

Black eye gobies are always curious, coming by to see what you are doing and smiling at you

Two similar nudies are Porters and MacFarland; you tell them apart by the number of stripes. Porters has 2 syllables and 2 stripes, MacFarland has three of each.

And finally there are clowns.

Overall, I am very pleased with the performance of the GTM strobes. I didn't have a chance to see how they would be for wide angle (mostly the visibility was 2 meters or so) but at least in the studio they seem as powerful as the YSD3.

If you are looking for strobes for macro shooting with some occasional wide angle take a look at these.

Bill

I have long fascinated with shooting ring lights underwater starting with the Inon Quadflash, through the various Athena modifications to Sea and Sea strobe heads, continuing to the Saga fiber optic rings and now to the Weefine 3000. The Weefine 3000 is the latest version of the LED lights made by Kraken and Weefine. The Weefine 3000 CCW

It's similar to the earlier 3000 lumen LED modules but has adjustable color temperature and a 3000-lumen burst (strobe) mode. It also has a super closeup mode that can shoot subjects as close as 25 mm (1 inch) from the strobe. It is powered by a protected, 26650, 5000 mAh Li battery. The battery can be charged via a built-in USB-C port.

One very neat thing about the light is that it allows for a very small, compact system underwater. No arms necessary, just the camera/housing/port and a single fiber optic cable. The light is shown below on an AOI housing for the OM-1 camera.

The ring light can attach to any port with a 67 mm thread and can be rotated for any angle once attached. One nice feature (or bug) is that when you are using the light in the strobe mode, it remains on at low power to act as a focus light. During the day it was not terribly necessary but worked fine at night, although you will also need some kind of dive light to find your way. My wife said it was very easy to find me in or small group, just look for the circular dive light.

How well did it work? Better than I had anticipated. Years ago, I had the Kraken version of this light, and it was fine; this version with improved ergonomics (no multiple button pushes) worked great.

Here is a nice little clown (Triopha catalinae) from a dive in local Southern California waters before the Raja/Triton Bay trip on the Wellenreng.

Overall, the light worked well for the things I was shooting, it of course is completely useless for anything more than 250 mm (10 inches) away. The color temperature is fine but shooting in raw lets me adjust as needed.

A friend used the light as a video light for a TG7 with a 52 mm to 67 mm adapter and said that for most nudibranchs the light was much easier to use than independent lights on arms.

I wish it had more power, a 6000-lumen burst mode for this type of light would be awesome, but the current version is adequate for micro 4/3 shooters and awesome for the smaller sensor cameras like the TG series.

Like most things, some attention to maintenance is usually a good idea. Underwater camera and cinematography accessories are no different, especially with the use and abuse most of it gets in unforgiving environments. Naturally, the better something is taken care of, the longer it will last, and even though Ultralight Camera Solutions products are virtually indestructible, treating them with respect will keep them in good working order.

For the underwater photographer, after every dive, the best thing to do is thoroughly rinse everything in freshwater, inspect and service it if needed so it is ready to go when needed. For most of us, it's easy to forget and overlook these things that will bite us in the butt later, especially when we decide at the last minute to go diving. Being proactive is always better than being reactive.

To learn more about caring for and maintaining your underwater photography accessories, we have put together some information and videos that you can view at the link.

Backscatter Smart Control Optical TTL Flash Trigger Review & Setup Guide

[Moderators Note: Waterpixels member, James Emery, is the Marketing and Media Manager at Backscatter]

The Backscatter Smart Control Optical TTL Flash Trigger provides super-accurate, automatic flash exposures with Olympus/OM System and Sony cameras using Backscatter strobes. The Olympus/OM System trigger is TTL compatible with the Mini Flash 2 and Hybrid Flash, while the Sony trigger is TTL compatible with the Hybrid Flash. The Backscatter Smart Control Optical TTL Flash Trigger is more than just a TTL trigger, it also can be used for manual triggering, rapid firing over 30 frames per second, and HSS (high speed sync), all built into a self-contained USB-C rechargeable unit.

The Backscatter Smart Control Optical TTL Flash Trigger has three different models, two universal types for Sony and Olympus/OM System cameras, and one for Nauticam full-frame Sony housings.

Watch the video for the key features of the Backscatter Smart Control Optical TTL Flash Trigger

Watch Our Full Review of the Backscatter Smart Control Optical TTL Flash Trigger

Smart Control Optical TTL for the Most Accurate Results

Underwater systems utilize different methods to achieve TTL through a camera, housing and strobe, including hardwired TTL, digital optical TTL, and S-TTL (slave or mimic TTL). The Backscatter TTL trigger uses a digital optical system in the form of Smart Control Optical TTL, which is a proprietary TTL system, to achieve accurate results.

CLICK HERE TO KEEP READING

Without a doubt the Olympus TG Tough range have revolutionised the world of underwater photography for both snorkelers and divers in recent years, making incredible results achievable for the beginner as well as giving a vast variety of options to expand creativity.

But with so many options for accessory lenses and makes available, what should you be looking for if you want to start adding a creative wider angle to your images.

This festive period I was super busy helping answer some of the popular questions that I see on other forums so I've put this together in the hope that it might help someone else too.

So let’s start as a snorkeller.  Is a housing really needed?  Personally I’d always suggest one, even if it’s just to have that extra security measure and of course remember that you will need one to add on extra wide angle lenses at a later date.  Not only have I seen them flood in the water for no apparent reason but it’s all too easy in the excitement of getting in the water to accidentally not close the battery door or overlook a tiny pesky hair trapped in the seal.  When you’re travelling to unique, once in a lifetime destinations, it’s always better to be safe.

Then there’s the option for snorkelers to add on an Olympus FCON-TO2 (which is also waterproof) directly to the Olympus TG range via an adaptor, CLA-TO1, with just one easy click.  This will give you a wider field-of-view than the camera’s own 25 mm one and is great if you are using the camera above water too for wide landscape images.  It’s great for small reef scenes, but for larger subjects such as this seal above, a wider field-of-view is needed to fit more of it in.  It also struggles with above and below shots.

But if you use an Ikelite Housing with a dome port for your Olympus TG, you can simply just pop the camera and the FCON-TO2 lens into the housing, giving it a much wider field of view so you CAN capture much wider scenes, achieve split-level shots too and create a perfect snells window effect when framing a

subject above you.

The Pros are:-

• the edges of the image are sharp and there’s no vignetting

the system stays light (just over 1 lb for the whole unit) compared to adding on a wide-angle lens directly to the front of a different housing which can make the housing tip forwards and downwards, even with a tray to help balance it.

The Drawbacks are:

• keep an eye out for black corners to your image as the dome shade may interfere with the overall result and if this happens, simply remove it.

Did you know that with this set-up you can actually zoom through the lens to achieve sharp close-up images too?  Check out Ikelite’s website or direct link here to see how it performs underwater:

https://www.ikelite.com/products/dome-port-for-olympus-fcon-t02-lens-and-adapter-kit?pr_prod_strat=pinned&pr_rec_id=ec369bea4&pr_rec_pid=3943133118533&pr_ref_pid=11527790933&pr_seq=uniform

So let’s look at other wide-angle lens choices.   A super popular choice with many starting out is Backscatter’s M52 Air Lens or AOI’s Underwater 0.75x Wide-Angle Air Lens (weighing 20 grams underwater/160 gms on land) which give an 81 degree angle of coverage, sharp corners, is light and easily screws into a 52 mm threaded mount.   It works perfectly to restore the camera’s  topside field-of-view underwater and at the same time will restore your image’s colour, sharpness and clarity by reducing the water column, therefore allowing you to get closer to your subject.  It has an Anti-Reflection Coating too.  You can also zoom through this lens to take full advantage of the TG’s Microscope Mode.   An extra super useful touch is that you can attach the lens to your housing via a lanyard (a very thoughtful touch which is included with your purchase) which will keep your lens safe when you are underwater.

It’s a great lens for turtles, large fish like groupers, divers and small reefscapes.

I loved using this lens when I had the chance to photograph blue sharks off the coast of Cornwall with my Olympus TG-6  It produced detailed results as you can see here, but I really needed a wider field-of-view to be able to capture the whole body of the shark to be able to have a sharp result throughout the image.

So do you really need to go any wider and why?  For all those cave, wreck and super wide reefscape scenes with or without a modelling diver, this is where a wider angled wet lens really shines to capture both dramatic and creative images.  There are a few makes to choose from such as Kraken, Weefine, INON, AOI and of course Backscatter!

Let’s look firstly at Backscatter’s M52 120 degree Wide Angle Lens

Backscatter have done a sterling job to design and innovate wide-angle lenses especially designed for the Olympus TG series and this lens is fabulous for those dreaming of capturing those captivating wider angled scenes.  Like the Air Lens, it delivers sharp corners, there’s no vignetting (where little black areas appear in the corners of your image), has an Anti-Reflection Coating and you can zoom through the lens for those all important close-up shots, making it perfect for capturing Close Focus Wide Angle Images.

Want to go Ultra Wide to capture even more of those wreck, pier or scenic cave shots?  Weefine has designed a super wide conversion lens (depth rated to 60 ms) which offers an incredible 150 degrees at 24 mm and easily screws into an Olympus TG housing’s 52 mm thread mount.  It also comes with an adaptor for 67 mm thread mounts.  Just be careful as the weight of the lens is heavier than the others (690 gms in the air/255 gms underwater).  It has a multi-layer BBAR coating for anti-reflection and optical clarity.  It has an optical grade polycarbonate dome which is easy to repair if needed.  Again you can zoom through this lens if needed.  A super wide lens is incredible useful for close-focus wide angle images, allowing me to get much closer to my subject and with the use of just one strobe placed over the middle of my housing, I could illuminate the above subject. 

Kraken has also its own KRL-02 52 mm Wide Wet Lens which offers a 145 degree at 24 mm.  It has also been designed with a 52 mm thread, also has a multi-layer BBAR coating for anti-reflection and optical clarity purposes.  It also has the capability to zoom through the lens for a tighter frame.

Just be aware that vignetting (black edges to the corners of your image) may still occur with different housings and lens combinations.  If you notice this, just simply zoom slightly until the effect disappears.

So there you have it, an introduction to the wonderful world of wide-angle creativity.   Wide-angle has been my calling in the world of underwater photography and there's nothing more that excites me than creating a unique scene which captures guests' attention and creates a conversation to encourage them to explore our underwater world too.

Warm Seas,

Maria 

There's absolutely no doubt that smartphones are an incredible, cost-effective way to get started in underwater photography.  There’s nothing more exciting than being able to view and upload your images to social media as soon as you finish your dive, on a safety-stop or even whilst snorkelling .

Did I say started?  Let me take that back, as it is so easy to get addicted to using one, that you may just want to ditch your usual camera in favour of it.  Of course there are advantages and disadvantages of choosing a smartphone over a camera, but for ease-of-use and for a complete beginner, they are a total game changer.

So with so many different housings available for your phone, so I thought I’d share some views on two of the most popular housings Divevolk versus Sealife.  I’ll cover other popular housings like those made by Kraken and Oceanic soon.

Sealife SportDiver Ultra Smartphone Housing - Depth Rating 40 metres/130 ft - $349

Both compact and sturdy (ideal for where I am in the UK), this housing is how I fell in love with shooting with my own iPhone and has been voted as Scubalab Tester’s Choice for 2024.

The SportDiver Ultra housing is a heavy duty housing (808 grams) and is made of polycarbonate, stainless steel, aluminium and optical grade glass.  It will take all iPhones from iPhone 8 through to 15 Pro Max as well as most Android models.  Just made sure that you review the Sportdiver compatibility and fit guide.  It has it’s own SportDiver App which connects to your phone through Bluetooth Low Energy 5 wireless technology, using the phone camera’s technology which is native to each camera.  The housing itself is powered by two AAA batteries which last over 50 hours of continuous use.  It is almost neutrally buoyant and Sealife also make a Gear Retractor which is a stainless steel snap clip which attaches to your BCD to keep it extra safe when it’s not in use.

Let’s look at what the Sport Diver housing offers:-

• It has a generous shutter button at the top of the housing and four easy-to-use buttons on the back, making access to the different settings easy to use, especially when you are shooting in colder water with gloves.
• It has the ability to change the ISO, Exposure Value, White Balance, Adjust Zoom, Tint, Lens Selection plus the ability to shoot in both JPEG and RAW, making it ideal if heavy editing is your passion afterwards.  Video stabilisation is also available on certain phone models.
• It is equipped with dual Leak Alarms which include a moisture alarm and a vacuum pressure alarm, alerting the user with on-screen warnings.  This alarm will even notify you on the surface if it detects even a drop of water in it and trust me, you will definitely hear it!
• It also as a Vacuum System with a pump to create more security for your system.
• It has a very sturdy build which is suited for more challenging conditions.  It also has a sturdy holding spring and rubber grip tabs which securely hold the smartphone in place and add shock-protection.
• Automatically comes with a removable red filter (with a safety tether) to restore natural colours in tropical water and a sturdy travel case so you can get started immediately.  Both magenta and yellow filters are also available.
• Interior fogging and condensation are prevented by using “Moisture Muncher” capsules.
• Looking to get creative?  A 52 & 67 mm thread adapter is available for both macro and wide angle lenses.  At present there is just one wide angle dome lens available (which is positively buoyant and has a safety lanyard) increasing the phone len’s field-of-view by 40%.
• The housing features seven 1/4-20 tripod mounts to mount any light or light tray with standard tripod threads such as Sealife’s range of Sea Dragon underwater photo/video lights.
• Your phone can be taken out from the back door to charge.
• The Playback Mode shows full size photos and videos with a vertical thumbnail strip, making it easy to locate your images.  Files are also saved automatically to your phone’s camera roll.

The downsides are:

• It needs to be used with the Sealife App for it to work, so all of the functions aren’t accessible such as the highest quality video setting available in newer iPhones.  Some of your phone settings may not be available through the App, so it’s important to check both the App and Play store for SportDiver App updates.
• A manual vacuum pump (included in the set-up) is needed.

You can read more about all the different options available via Sealife's website here:-

https://www.sealife-cameras.com/product/sportdiver-ultra-smartphone-housing/

DIVEVOLK - Seatouch 4 MAX - Depth Rating 60 metres/196 feet - $239

It’s safe to say that Divevolk have taken the smartphone underwater photography market by storm by introducing the first ever fully integrated touch screen which makes all of your favourite apps and functions easily accessible underwater at an affordable price as well as offering the widest range of add-on lenses.  Trust me, you’ll be spoilt for choice as to which one to start with!  You can even communicate with your dive buddy underwater via writing apps, make an emergency call at the surface if needed as well as record GPS co-ordinates.   You can even have your own Fish ID Guide with you whilst you’re diving, making identification an absolute breeze.

The Divevolk housing is much lighter (375 gms), made of plastic and stainless steel, supporting any smartphone.  Simply pop your phone in a customised adapter and slide it into the housing through a narrow opening and close the housing door which has a built-in compression ring.  You’re then all good to go.

So let’s look at what it offers the user:-

• All functions are easily accessible via the touchscreen, even with wetsuit gloves.  And yes, the touchscreen is tougher than it looks with a special 3-layer sealing gasket to keep the housing secure.  For those colder water temperatures, this innovative company have even invented a special finger cot to pop on over your drysuit glove.
• It may not have a vacuum pump but it does have a pressure balance system to keep it safe from leaks.
• If film making is your passion, this housing is the only one to give you a choice to shoot at the highest resolution that your phone can offer.
• It can also be used as an external monitor for your d-SLR or Mirrorless camera.  It has developed a wi-fi transmitter which can be placed in-between your housing and your phone where the signal is transferred.  Divevolk is the only manufacturer to offer this option.
• Incredible underwater content can easily be achieved using the variety of add-on lenses which Divevolk offer.  From both red and magenta filters to a 15 + close-up lens, plus both wide angle and dome lens options make this an unbeatable system to get started with and grow your creativity.

The downsides are:

• Take added care to protect the membrane when travelling.
• If you are using a tray with two handles, be aware that you will need to remove the housing from the tray first before being able to remove your phone from it’s side door.  Alternatively you can purchase Divevolk’s own tray which allows it to swivel and you can then remove it easily.

DIVEVOLK Platinum - Depth Rating 262 ft/80 metres - $399

This recently launched housing has been specifically built for newer and thicker smartphones and has a much more sturdy finish.  It has the following upgrades:-

• It is made of aluminium alloy which makes the casing more resistant to corrosion.  It also makes it look very stylish.
• An upgraded sealing system, making the housing feel more resistant to leaks.
• The touchscreen is easier to operate with gloves and offers a smoother response than previous models.
• It comes with an integrated expansion clamp which attaches directly to the case with 1/4 inch threaded holes at the bottom.

For more information on Divevolk, visit their website here:-

https://www.divevolkdiving.com/en-gb/collections/seatouch-4-max-kit

Finally, don’t forget to utilise a wireless charger if possible to reduce the risk of moisture entering your housing.  Regardless of which one you choose, you sure are guaranteed a whole new underwater photography world opening up in front of you.

I’ve absolutely loved shooting with my phone the past couple of years for ease-of-use and the simplicity and how I can create my content for social media in a nano-second after getting out of the water.

I look forward to hearing your thoughts, experiences and seeing your images 🙂

Maria

Underwater Photography conjures up a vast array of subjects to capture, from the tiniest animals on the planet measuring just the size of a grain of rice to the largest creatures which have ever lived in our incredible blue planet.

But starting out as a complete beginner with such a huge choice of different compact camera systems to choose from and accessories, where on earth do you start to ensure that you come back from your trip of a lifetime with fabulous eye-catching images.

Compact cameras have evolved hugely from when I pioneered the first ever dedicated courses for them back in 2005, but the essentials I always ask on the forums I participate in are:

What are your dream images to photograph?

Where are you going?

How much do you want to change your settings?

What is your budget?

It’s honestly that simple to make sure that you choose the right equipment.  I remember seeing on one forum that a lady going to Fiji was recommended an Olympus TG6 for it’s macro capabilities.  Being the passionate shark stalker and wide-angle reef scene passionate that I am, I just had to butt on in and suggest that a wide-angle lens was an absolute must to capture those jaw dropping reef scenes that Fiji is so famous for, as well as those sharks.  Yes the macro life is absolutely incredible too, but it’s so important to KNOW your destination, RESEARCH the subjects which you are going to have the opportunity to capture and have a budget in mind to start with.  How can you go to such an incredible, jaw-dropping, life changing destination and NOT come home with all of the incredible images that both you and your camera deserve?

Then there’s the question, do you need a camera with full manual controls or not?  Again, it all depends on what you want to achieve, but I’ll never forget my course guest Daniel Norwood, now Editor of DivePhotoGuide winning the British Society of Underwater Photographer’s Best Beginner Competition with a compact camera which had NO manual controls.  The Runner-Up  (27 points behind) was the then Chairman with a d-SLR system.  It just goes to prove that it honestly is all about how YOU drive the camera, how YOU create an image, and that you CAN still create award-winning, breathtaking imagery with older compact cameras too.  I have a huge variety of all kinds of images taken during my 20 year career gracing the walls of my gallery here in the UK.  And guess what, no-one can tell the difference as to which one was taken with a d-SLR, Mirrorless, Compact, Go Pro or my Phone.

So let’s dive on in and look at some answers to common questions I often see to get you started on your own journey.

Do You Need the Latest Model of Compact Camera?

Absolutely not, I loved shooting with my Olympus TG4 before upgrading to a TG6 model.  If an older model will give you more “bang for your buck” and enable you to purchase additional lights or lenses so that you can achieve your dream images, then it’s totally cool to go down this route.

Which is the Best Compact Camera for a Beginner?

All of them!  Yes honestly!  It all depends what you are looking for and how much effort you want to put into changing different settings when you are underwater.  I even absolutely loved using my Sealife DC-2000 camera and in the right scenarios would deliver incredibly sharp, punchy images even here in the UK with minimum effort and fuss.

So do you need full manual controls to take incredible images when starting out?  Absolutely not!  Yes, full manual controls allow you to get more creative, but they are not the be all to creating fabulous images that you will fall in love with.  I love the Olympus TG range for simplicity and for the jaw-dropping close-up images which it creates from the tiniest creatures by just using it’s “Microscope Mode.”  It doesn’t have full manual mode, but you can still achieve black backgrounds to your close-up subjects by adjusting some in-camera settings.  You can add-on wide-angle lenses, lights or even use a torch to start your creative journey.

Can I Really Capture Great Stills Using a Go Pro?

Holy moly, yes, yes, yes!  I’ve fallen in love with my Go Pro this summer and all the additional lenses and accessories which you can add to it.  From Backscatter’s MacroMate Mini which neatly fits on the front of a Go Pro housing to achieve razor sharp macro images to their incredible (how much am I in love with this lens) Action Cam Sharp Wide Lens Pro which gives a whopping 140 degree field-of-view.  It also allows the Go Pro to focus much closer to your subject to give you real nice close-focus wide-angle images.  Simply add on some small video lights to bring extra lushness, colour and depth to your imagery, I love my MARES EOS 10LRW Video Light Set-Up for lightness, compactness and brilliant results, and you are set to go.

What About Using My Phone Underwater?

Can you guess what I’m going to say?  Yep I absolutely ADORE using my phone underwater as well.  It also will give you excellent results, and it really is all about what you want to achieve our of your underwater imagery.  For me, what sets it apart from the rest is that your images are there as soon as you finish your dive, ready to upload to the world without the need to download them first.  I have been using a Sealife Housing and I love being able to change different settings via the Sealife App such as ISOs, Exposure Values and I can even shoot in RAW.  Being able to change my exposure value was crucial to achieve these reflections at Ginnie Springs in Florida.

Finally what about Insta 360?

Insta 360 is definitely all the rage at the moment, and definitely so for a very good reason.  You will not have seen anything quite like it anywhere and the results will leave you spellbound.  That is as long as you are using it in settings which actually suit it’s capabilities, such as huge wrecks, large reef scenes and giant cave systems.  Oh and make sure you have heaps of ambient light around you to get the best results.  Trust me it really is awesome, but you will need to take extra care with the lens as it scratches easily.    Sadly you can’t add any extra lights onto it due to the way that it has been designed, but trust me, it is jawsome.

I could honestly write about all of them forever, but thought it best to stop here so that you can go grab a coffee.  At the end of the day, they all take superb images, but you need to make sure that you are in the best possible conditions to make the most out of each device.  I’ll write more to explain each set-up individually very soon.

Until then, feel free to reach out and ask me any questions.  Helping is my middle name so just reach out if you’d like some help.

Look forward to seeing you all very soon.

Maria

Sony and Panasonic underwater macro photographers shooting full frame should checkout my latest review in UWPMAG.com issue #141. It fully details the Sigma 105mm F/2.8 macro for FE and L-mount cameras. I reviewed the Sony version of the lens using Marelux housing, ports, strobes and Marelux closeup lenses +10, +15 and a +5 including stacking two lenses. If you are looking for a quality macro at a reasonable price or wanting to add to add an additionaly macro lens this may be the lens for you.

Disclaimer:

Thanks to Pietro Cremone, the Italian distributor of Nauticam, I had the opportunity to try out this interesting lens on a recent trip to Anilao for blackwater dives.

Blackwater diving is a form of night diving that involves exploring open waters off oceanic coasts. Unlike traditional night dives, which take place near the shore or in shallow waters, blackwater dives occur in deep waters, typically offshore over deep ocean floors. During these dives, divers immerse themselves in dark waters, often with depths exceeding 100 meters. A bright buoy connected to a variable-length line (20-30 meters) is placed in the water, to which very powerful torches will be attached.

The lights are used to attract plankton and marine creatures to the surface, offering divers the opportunity to observe these unique creatures up close and appreciate their beauty in a completely different environment. Additionally, the lights serve as an optical reference for divers as they drift with the currents alongside the buoy and line.

Blackwater diving can be an extraordinarily fascinating experience, but it requires adequate preparation and some experience with night diving. Divers must have excellent buoyancy control and perfect self-management skills, including with their photographic equipment.

In recent years, these dives have become very popular, especially among underwater photographers, who can capture stunning images of animals that normally inhabit oceanic depths and, thanks to currents and the upwelling phenomenon, ascend towards the surface. Among these creatures, one can find zooplankton, larval stages of many fish species, mollusks, shrimp, etc., and even rare encounters with Paper Nautilus or the Blanket Octopus.

Locations for this type of diving are scattered around the world, and the most famous ones with dive centers with greater experience can be found in: Anilao in the Philippines, Hawaii in the USA, Palm Beach in the USA, Lembeh in Indonesia, and Cozumel in Mexico.

For photographic equipment, it is recommended to use a macro lens with a 1:1 ratio and a good field of view (ideally 50 or 60 mm equivalent full frame), with good AF speed, two strobes, and a focus torch positioned on the housing to assist the AF system of the camera body, and a narrow-beam torch for searching subjects, which can also be positioned on the housing or held by hand.

For photographers using Nikon or Olympus, they are fortunate to have two excellent lenses available: the Nikon AF-S 60mm f/2.8 G ED Micro and the Olympus M.Zuiko Digital ED 30mm f/3.5 Macro, which are perfect for Blackwater photography.

However, for Canon and Sony photographers, it is unfortunately more complex because the available optics have very slow AF (Sigma 70mm f/2.8 DG Macro Art and Sony FE 50mm f/2.8 Macro), and in Blackwater, it can be frustrating to try to focus as we really have to seize the moment: subjects are free in the water and besides drifting, they move constantly, making it much more difficult to capture correctly.

Using more performing lenses like Sony FE 90mm f/2.8 Macro or Canon 100mm f/2.8 L Macro unfortunately becomes more complex, even though they have a good AF speed, due to the narrow field of view.

An interesting solution to solve this problem is provided by Nauticam. In recent years, Nauticam has been investing heavily in "wet" optics, such as the WWL and WACP-C series, to name a few. In 2020, Nauticam launched a new system of wet optics on the international market, the EMWL series (Extended Macro Wide Lens).

The EMWL is designed to work with various macro lenses and is optimized for both photos and videos. It is a "wet" mount design so that the lens can be attached and removed underwater. This increases the versatility of the entire system. EMWL is a modular system composed of three main parts: the focusing unit, the relay module, and the lens. Plus, an accessory for quick mounting. On the Nauticam website, you can find a detailed description of its features and the modules that compose it. 

Being a Canon user, I have strong limitations on the lenses to use in BW, and I thought this lens could help solve them.

The setup I used is as follows: Canon R7, Canon EF-S 60 macro, Nauticam NA-R7 housing, N100 flat port 74, Reverse Angled Viewfinder 32º, EMWL Focusing Unit #1, and 60° objective lenses.

Pre-Dive Considerations

It is important to note that the EMWL is a lens designed for underwater use and must be immersed in water to function properly. When testing the flash before the dive, it is necessary to get very close to the object, about 1 cm, to make the camera's autofocus work. If you photograph in the air, the autofocus will not focus on anything; immersion of the lens in water is essential. However, at a distance of 1 cm from the lens, autofocus works and allows testing the flash dry.

The EMWL is composed of heavy optics. On the Nauticam website, you will find tables for each part of the EMWL. In my specific configuration, the Focusing Unit weighs 728g, the Objective Lens 60° 378g, the Reverse Viewfinder 700g, and the M77 to BM II 122g, for a total of 1,928 grams to add to the normal configuration without a 45° Viewfinder. In my case, I use the normal 45° Viewfinder and should subtract the weight of mine, which is about 480g. So, compared to my base configuration, I add a weight, out of the water, of 1448g. I emphasize this point because on my first dive, I didn't worry at all about the additional weight, but using the camera with this extra weight was a bit more complicated in normal BW use. I recommend neutralizing this additional weight as much as possible with floats or floating arms.

In-Water Use

With a 60° field of view, framing subjects becomes significantly easier, which is definitely the strong point of this system. This allowed me to quickly and better frame the subject through the Viewfinder. Locating and focusing on the subject was significantly simpler with this lens, allowing me to track it and get as close as possible.

The autofocus was not affected by the additional lenses of the Nauticam EMWL system. The focusing systems, single-point AF or AF tracking, worked perfectly. I did not notice any differences compared to normal use. I only experienced a worsening when using the red color of the focus lights. With subjects more sensitive to white light, such as Squid or Paper Nautilus, I usually use only the red color of the focus lights. However, with the EMWL, changing the color of just one focus light from red to blue or white, the autofocus work perfectly again.

The Objective Lens 60° has the ability to adjust the minimum focusing distance in 3 modes; surely the 55mm-infinity adjustment is preferable for blackwater photography. Searching for the minimum focusing distance, especially for smaller subjects, framing becomes more complicated, but I noticed a greater magnification of the subject. Comparing notes with Pietro, he confirmed that the 60° lens can achieve a magnification of 4x at the CFD, and this is another advantage of this system. Obviously, for smaller subjects, it is always more difficult to get a good shot, but with this lens, we could photograph other subjects that we normally give up on because they are too complex or have obtained poor results due to the 1:1 ratio of the lenses used up to now.

Another impression I had is that the lens provides a greater depth of field. Reviewing the shots taken of a male Paper Nautilus attached to a tunicate, I noticed that a good part of the tunicate and the Paper Nautilus were well in focus. However, I did not have many similar shots during this test session.

The only "negative" feedback I can provide from my experience using it in blackwater is that occasionally, on slightly overexposed shots and with highly reflective subjects, the lens produces a white halo around the subject. In the shots taken, the number of files with this issue was negligible, but I felt it was important to mention it.

Final Thoughts

I was thrilled to use this system, and I would like to thank once again the Italian distributor of Nauticam (Fotosub-shop.it - Pietro Cremone) for giving me the opportunity to test it in black water. Certainly, this system requires various trials in the water by the user, but once the right balance is found, it can provide incredible images of both typical subjects in blackwater and smaller subjects. The cost of the complete configuration may not be within everyone's reach, but as we know, our hobby is expensive, and we do enjoy expensive toys. If you have the opportunity to purchase it, you could overcome the limitations we have with the lenses used in blackwater. If I have the chance to try it again, I would like to use the 100° lens for larger subjects, such as a Blanket Octopus (if they are easy to find), a beautiful female Paper Nautilus, or a large jellyfish; it could be very interesting, considering also that changing lenses can be done underwater, being very careful not to let it slip, though... I will keep you updated.

Hydrozoan Jellyfish - 1/320 F14 ISO 320

Tube anemone larva - 1/320 F14 ISO 320

Flounder larva - 1/250 F16 ISO 320

Mantis shrimp larva - 1/250 F16 ISO 320

Crab larva - 1/250 F16 ISO 320

Unidentified - 1/250 F16 ISO 320

Juvenile benthic octopod on a salp - 1/250 F20 ISO 320

Juvenile benthic octopod on salp - 1/250 F22 ISO 320

Seahorse, Hippocampus sp. - 1/250 F18 ISO 320

Dotterel Filefish - 1/250 F20 ISO 320 

Veliger larva - 1/250 F16 ISO 320

Shrimp larva - 1/250 F16 ISO 320

Mantis shrimp Larva - 1/250 F18 ISO 320

Fish larva - 1/250 F16 ISO 320

Underwater photography is an incredible experience because it offers enthusiasts the opportunity to discover the underwater world in its most authentic beauty. To capture these extraordinary images it is essential to have the right equipment, and one of the key elements in underwater photography is the strobe.

SUPE Scubalamp is a company specialising in the design and production of underwater lighting equipment, including torches, strobes and related accessories. The company, a world market leader for many years, recently launched the new SUPE Scubalamp D-Pro underwater strobe, successor to the glorious D-Max. This product caught the attention of the underwater community due to its exceptional quality, light uniformity and battery life, and these features immediately placed it among the best in the industry. Another distinguishing feature is the high-speed continuous shooting mode, with the strobe supporting 10 frames per second in the first mode, making it much easier to capture shots in quick succession.

The D-Pro, with its 4800 degree Kelvin circular lamp with a 160W power output and 150 degree beam angle, ensures an even spread of light over the entire framed area. This means that captured subjects and scenes will appear in natural, vivid colours - in short, your shots will be outstanding.

A crucial feature for underwater strobes is battery life. While in the deep sea it is complicated to change batteries easily, so to avoid any kind of problem it is always preferable to do the replacement only at the end of the dives. SUPE Scubalamp D-Pro also excels in this respect, thanks to its 37.8 Wh rechargeable lithium battery (3x 18650), which guarantees from 500 strobes at full power up to 3000 strobes in the first mode. The large battery capacity supports long underwater photo sessions, allowing every moment to be captured without interruption. The strobes also feature a display that shows the battery charge status, allowing you to keep track of the remaining battery life at all times.

I have been fascinated by these strobes since their launch and, after hearing feedback from other underwater photographers, I finally had the opportunity to test them first-hand during my recent three-week trip to the breathtaking tropical waters of Raja Ampat, Indonesia.

The setup I used for the test consisted of: Canon EOS R5, Canon EF 8-15mm f/4L Fisheye, Nauticam NA-R5 housing, Nauticam 140mm Dome, Nauticam Trigger and Flex-Arm carbon arms.

During the first dives I studied the light behaviour of the strobe in order to position it in the best possible way. The circular lamp guarantees excellent uniformity in light distribution and the D-Pro, with its coverage angle of about 150°, provides a considerable amount of light perfectly distributed over the entire frame of the shot. Power adjustment is easy thanks to the power selector. To balance the weight I added a pair of floats, as the strobes tended to be slightly negative.

Looking at the shots underwater, previewed on the camera, I was impressed and couldn't wait to review them on my computer once back on land. Upon review I was even more surprised by the quality, quantity and uniformity of the light, everything was simply amazing.

While diving, I tried to 'exploit' the strobes to the best of my ability in a variety of situations, and they never let me down; on the contrary, they always provided the best of their light. I was particularly satisfied with the battery life. I always recharged the batteries after 6 dives, with an average of about 100-130 shots per dive, the display allowed me to accurately monitor the remaining charge, eliminating uncertainty about whether I could continue shooting. Recharging the batteries was simple, just remove them from the compartment and plug them into the supplied transformer, waiting for the LED to turn green to indicate a full charge. I'm not sure of the exact hours needed, I always did this before going to sleep, in the morning the batteries were ready, fully charged.

As an optional extra Supe supplies a diffuser (D200-Diffuser) for wide angles. It is a hotly debated topic among underwater photographers whether they should be used or not. Not being able to provide scientific measurements with appropriate instruments, I can only give you my personal feelings.

I felt good in both cases, with and without, the difference I noticed was only in the type of scene shot. I shot very often without a diffuser, because I had the feeling that the strobe had more penetration and the light was more incident on subjects with a greater distance to the lens. On the other hand, with very close-up shots, I found the shots with the use of the diffuser with a softer and more even light more pleasing.

After three weeks of diving I did not experience any problems with their operation, the strobes were always ready to fire. The size and weight did not have a major impact during the dives, I appreciated their ease of use. I personally think that the SUPE Scubalamp D-Pro is currently one of the best underwater strobes available on the market in terms of value for money. However, it is important to emphasise that I have not been able to assess its reliability in the long term; my testing period was, in fact, limited. However, I am also confident in terms of reliability because the quality I found during use was evident.

 I would like to thank my friend Scipione, who allowed me to test these strobes, and Raymon Bao, owner of SUPE Scubalamp, who was always available to answer my requests for further details about the product.

F8 - 1/125 - ISO 100

F11 - 1/160 - ISO 320

F13 - 1/160 - ISO 250

F10 - 1/125 - ISO 250

F8 - 1/160 - ISO 250

F11 - 1/125 - ISO 250

F10 - 1/125 - ISO 200

F8 - 1/125 - ISO 160

F9 - 1/125 - ISO 200

Last year I decided to go big - switching from the tiny RX100 to FF (FullFormat). In my case, it was the A7IV as the best value for money. But having made the decision on the camera model is only one step - lens, housing and port is much more difficult. But with the support of the nice guys here and the old forum, I am now the happy owner of a sleek combination that is tailored to my needs. But how do you know what you need? This article might help.    

The most common type of camera used by underwater photographers is one that is inserted with lens into a housing and has either a flat (flat port) or curved (dome port) front glass at the port.

Even in the days of analogue photography with the Nikonos system, for example, water contact lenses were developed that explicitly take into account the refraction of light at the water-to-glass contact surface. This reduces distortions that would otherwise occur when light hits the port at an angle and cause blurring at the edges.

Nauticam has therefore developed some different types of water contact optics that evolved and serve different purposes.

FCP (Fisheye Conversion Port) and WACP (Wide Angle Conversion Port) are "dry" optics designed to turn a mid-range zoom lens on the camera into a wide-angle zoom when the combination is taken under the surface. WWL (Wet Wide Lens) is the older version, somewhat less compact and made of more components, wet lens, but otherwise very similar to WACP.

EMWL (Extended Macro Wide Lens) takes a different approach: different underwater lenses are placed in front of a macro lens and a flat port in order to be able to adjust on different subjects - from macro to large fish.

First and newest: FCP 

Picture courtesly provided by Alex Mustard

A dry lens that is attached directly to the housing with the appropriate (depending on the camera and lens) port extensions. 

In concrete terms, you can imagine the FCP as an ultra-wide-angle lens for underwater use. A lens such as the Sony 28-60, Canon 24-50 or Nikon 24-50 is attached to the camera and the FCP is mounted on the housing. This achieves a maximum field of view of 175° - a real fisheye. In the zoom position, the field of view is still 85°, i.e. still quite wide-angle, comparable to a 24mm lens over water.

Next WACP: Still new, especially the WACP-C

The WACP ports with the endings -C for compact, -1 for the "normal" variant and -2 for the maximum variant are not quite as extreme. Also "dry" optics - see above. They are intended to cover a field of view of approx. 70°-130° - i.e. comparable to a lens with a normal focal length (approx. 30mm) to a slight fisheye wide angle (11mm). On the camera, the WACP-C and WACP-1 require similar lenses as for the FCP (for example Sony 28-60, Canon 24-50 or Nikon 24-50), but the largest variant requires a wider-angle lens such as 14-30mm to achieve the same field of view. These water contact lenses are quite bulky and heavy (WACP-C: 2.3kg, WACP-1: 3.9kg, WACP-2: 7.0kg) and offer better sharpness than dome ports, especially at the edges, but above all they provide a wide zoom range under water and focus even directly at the glass. The WACP-C, although labelled as a compact version, also fits some of the full-frame cameras and is the most suitable solution for me personally. 

WWL-1(B): 

AFAIK the two WWL ports (WWL-1 and the newer WWL-1B) are the predecessors of the WACP ports. The area of use is the same as with WACP: field of view approx. 70-130°, i.e. wide normal focal length to slightly ultra-wide angle/fisheye when using zoom lenses with a focal length range of approx. 25-60mm. The difference to the WACP solutions is the technical design. With WWL, you have a compact plan port on the housing and the WWL is mounted wet, i.e. with water between the front glass of the port and the WWL lens. Advantage over the WACP solutions: lighter overall, and you can remove the WWL under water and then have a lightweight telephoto lens (...no one ever does...). Disadvantage: The telephoto lens is rarely needed and air bubbles between the port and the WWL can be annoying. 

EMWL: One size matters fits all

The EMWL wants to be and can be an "all in one":

The basic here is that an 90 mm macro lens is mounted on the camera and the corresponding port with flat glass at the front (flat port) is mounted on the underwater housing. A close-up lens (e.g. SMC-1) for magnification or the EMWL can be used on a flip port.

The EMWL consists of two or three elements:

• The focusing unit, which is available in variants for Nikon, Canon and Sony, is located directly in front of the macro port
• An optional extension piece (relay lens) then follows, which turns the image upside down and brings the front glass closer to the subject
• The actual lens, which is available in 160°, 130°, 100° and 60° angle of view versions, is located at the top. The 130° lens is particularly popular and is ideal for CFWA, but also for large fish or panoramic images.

In contrast to FCP and WACP, the EMWL is a wet lens, so there is water between the port glass and the focussing unit, but also between the relay lens and the objective lens. Image quality is high in every direction but bubbles between the parts can be annoying and there have been issues about focus breathing.

The main areas of application are thus:

FCP: Fisheye wide-angle zoom, medium volume, compact

WACP: Wide-angle zoom, medium to large volume depending on version

WWL: Comparable to WACP, Lighter and slightly cheaper, but with technical disadvantages

EMWL: fixed focal lengths that can be changed under water, somehow bulky, objectionable appearance

To show the differences in size and appearance here a pic from Alex Mustard, showing (left to right) FCP (prototype), WACP-C, WACP-2, WACP-1 (Thanks, Alex!)

Cost (€)? You have already camera, housing and lens. And focus gear. And port extension. And arms, flashes and so on. Just the port:

Rough estimates

FCP: EDIT Jan 14th: Now on Nauticam website €6.482,00 (incl. VAT)

WACP-C: €2.9k

WACP-1: €4.5k

WACP-2: €8.2k

WWL-1b: €1.9k (with flatport)

EMWL: €8.5k (with flatport, 60°, 100°, 130° optics, rely, focusing unit, flip-holder, SMC-1)

If I made errors or incorrectness anybody please feel free to add or correct

This article is a short version of the original post that can be found on my blog. The content is very much the same but this version is slightly shorter and has less opinions than the original. Those opinions are personal and potentially controversial and I do not want Waterpixels to be associated with them.

Warning this is an extremely technical article that I have written on request. If you are not familiar with optics, geometry, housings do not attempt to perform a calculation by yourself and rely on expert advice.

Hope you find it useful, also the original PDF of this article for download is below. 

Methods to determine the appropriate dome port for a wide angle lens in an underwater housing - SHORT.pdf

Background

The physics of dome ports are not new to underwater practitioners although not many people understand the formulas, it is well accepted that there is a correct way to size and position a dome port in order to optimise opticalperformance of a lens inside an underwater housing. I do not want to repeat the theory here but if you feel you need a refresher the excellent articles from the now passed David Knight and specifically the piece on dome port theory will be useful. For the purpose of this article I will consider only underwater imaging, split shots and over and under have different considerations and will be addressed separately in due course.

Practical Implications

For our purposes, what is interesting is that a dome port is able to restore the lens air field of view when the camera and lens are inside a housing. The theory says that this happens when the centre of the dome lies on the lens entrance pupil. But what happens if it does not? Jeremy Somerville has created a number of visualisers that although not totally correct give a good idea of the issues involved. In particular the positioning of the dome port is something you may want to check. In short if the dome is not correctly positioned we lose field of view as result of distortion and increase the amount of chromatic aberrations.

We also have to consider that the dome port being a single element lens has also issues of field of curvature and spherical aberrations which are additional to any considerations on positioning and require the user to stop down the lens to reduce the side effect. Those side effects are exacerbated when the dome is not correctly positioned to the point they cannot be corrected no matter how much you stop down the lens.

Choosing appropriate wide angle lenses

Minimum Focus Distance

One of the key take aways of dome port theory is that if your lens is not able to focus close it may not work at all inside a dome, which in turn means your dome starts to become bigger and bigger to allow your lens to focus or you need to introduce close up lenses which further deteriorate optical quality.

More compact set ups and smaller domes require lenses that can focus close. In addition, due to the dome port optics, infinity focus will be reached at 3x the dome radius from the dome surface: your lens will work to a maximum focus distance well under one metre and closer to half a metre. This is a challenge for wide angle lenses that are designed for landscape and not usually optimised for close focus. One assumption that you cannot make is that a lens that is great for topside use will perform equally well behind a dome, or even more interesting a lens that is small and compact may require a quite sizable dome to work properly underwater which negates the size benefit to start with.

The dead Zone 

The dead zone is where the camera cannot focus because our subject is too close. Our objective is to place thedead zone inside not outside our dome so that we can maximise the range we can use for imaging. It is not an issue if the dome radius is so big that the focus area falls well inside the dome, in fact it may be an advantage, but if the camera focus distance is outside the dome we are eating away useful range and at the point where the focus distance is so far that is outside the dome infinity point the camera will not focus at all. By choosing a lens that can focus very close we accomplish two objectives:

1. We reduce the size of the dome required
2. We maximise the focus range that can be used.

I prefer lenses that have a minimum working distance around 20cm, and avoid anything that focuses from 25cm and beyond, this ensures good image quality and reasonably compact set ups.

Prime vs Zoom

Prime lenses have a fixed entrance pupil this means that once the dome is sized and positioned your job is done. Zoom lenses instead change in size or move the entrance pupil to accommodate changes in the field of view. This is bothersome as it means that if you determine your dome parameters at wide end this may not be correct at tele end. In addition as the angle of view is being reduced the curved surface of the dome will start looking more and more flat. This is a challenge but not one we need to address, as seen in the flat port theory lenses that are longer than 35mm suffer less from chromatic aberrations, therefore for our purposes we will treat zoom lenses like a prime lens whose focal length is the shortest our zoom can manage, i.e. the wide end of the zoom. At the tele end the dome with a zoom lens will look like a flat port but still have some benefit over it in terms of aberrations.

Zoom Factor

Although we said we will consider the zoom lens as a wide tele, lenses with a zoom ratio much bigger than 2x will most definitely be problematic. This is the reason why zoom lenses with conservative ratios like a classic 16-35mm are bound to perform overall better than say a 20-70mm lens. Lenses in the classic 24-70mm or 28-75mm range tend to have less problems because they are not that wide to start with and generally work well as long as they focus close, otherwise they will require larger domes.

Comparison at equal field of view and different working distance.

The graphic above illustrates how two lenses with equal field of view displayed in solid green require different dome radii depending on the minimum operating distance. The small inverse triangle is the area inside the lens up to the focal plane.

Lens1 will require the smaller dome so that the area not in focus falls inside the dome, if a larger dome is used this simply expands the focus range into the water proportionally to the increased dome radius. A lens with the same field of view but longer MOD2 will require a larger dome to ensure the area out of focus is inside the dome. A smaller domecan be used however the dead non focus area now moves into the water. As the infinity point is still set at 3x the domeradius from the surface using this smaller dome means less focus range can be used by the camera. Using too small domes deteriorates image quality because the compressed focus range has an impact on the overall image resolution.

Locating the Lens Entrance Pupil

In order to properly position the dome port we need to determine where the entrance pupil of our lens is. There are at least 4 methods that can be used to locate the entrance pupil of the lens.

Method 1 Look into the lens

It makes me smile when you read: locating the entrance pupil is easy just look into the lens and see where the aperture is. I do not find this easy at all, first lenses are increasingly complex in construction and second how do youplace depth of the aperture correctly even if you can see it? The error margin of this method is very high.

Method 2 Non Parallax Point

A demonstration of this method is beyond this write up however if you want to go deeper into this this article should help you. This method has a good level of precision and panotools maintains an entrance pupil database for many DSLR lenses.

Method 3 Trigonometry

Once you know the lens field of view you can use various filter rings to determine the thickness where vignetting occurs. At that point you can simply calculate the distance from the edge of the entrance pupil by taking the ratio between the lens radius and the tangent of the angle of view. This gives good precision and does not require anything else than the lens itself and a few filters but can be approximated also for a lens you do not own using standard roundings.

Method 4 Lens Design

There are some websites that have lens design drawings directly from patents. This will give you the exact location of the entrance pupil from the image plane and from the lens mount.

I use the site maintained by Bill Claff called the Optical Bench Hub. Unfortunately the database is not complete, some specific brands designs are scarce. The benefit of this method is that you can use it to make calculations before you buy the lens and it is 100% accurate.

Entrance Pupil Determination - Practical Examples

Case 1: Lens Design Available

We locate the lens design on the Optical Bench Hub here.

The important parameters are I distance from the edge of the lens to the image plane (sensor) which is 115.04mm and P distance of the entrance pupil from the lens front.

The difference I - P = 91.79mm still accounts from the flange distance. Taking that out we get

73.79mm from the lens mount.

The lens has a minimum working distance of 300mm. If we subtract the entrance pupil distance from the image plane of 91.79mm we determine a minimum dome radius of 208.21mm which is rather large and in fact not available if not as a custom product.

Case 2: Lens Design Not Available

The Tamron 17-28mm F2.8 is an affordable, fast and high quality wide angle lens with a somewhat limited zoom range. The lens is 99mm long and takes a 67mm filter thread. I used an ND1000 Hoya Pro filter with a thickness of 5.6mm, the lens external radius is 69mm with the filter on.

The lens nominal field of view is 103.70 degrees however all mirrorless lenses have software corrections. Ideally I need to know the real field of view however the error is normally 1 to 3% and does not influence the calculations too much.

If we consider a length of the lens and filter of 104.6mm and a radius of 34.5 mm for an angle of 51.85 degrees we obtain a distance from the lens mount of 77.5 mm and from the focal plane of 95.5 mm. Taking into account that the MOD is 190mm this gives a minimum radius of 94.5 mm for the dome which is very good news.

Dome Selection Part I - Field of View

The first thing that we need to ensure is that the dome field of view can contain the lens field of view otherwise our main objective of preserving the air performance would be lost.

Unfortunately the specifications of dome ports on the market are somewhat lacking so you need to make do with what you have or ask for CAD details.

I use Nauticam that do produce good documentation, zen does this too 

18809 18810 18812 1881318815 N120 Optical Glass wide angle port.pdf

Here you can see that, ignoring the thickness of the glass for simplification purposes the various ports have the following field of view using the formula 2*arcsin(glass port diameter/curvature radius)

It is somewhat surprising to see that the larger port in terms of size is the narrower in terms of field of view I believe this is a compromise in terms of weight.

Dome Selection Part II - Curvature Radius

Looking at field of view is not sufficient, we also want to ensure that the lens MOD is contained by the dome andtherefore we need to take into account the actual radius of curvature of the port

• 18809 180mm Optical Glass Wide Angle Port Radius 110mm
• 18812 230mm Optical Glass Wide Angle Port II Radius 120mm
• 18813/18815 250mm Optical Glass Wide angle port Radius 160mm

The port size goes with the curvature radius however somewhat surprisingly the difference between the 230mm and 180mm port is rather small making the choice between the two more a matter of field of view.

Amount of Recession of the Camera from the Port

Camera housings are not like skin, armed with a digital calliper you need to determine the distance between the lens mount and the housing port mount. Alternatively you can reverse engineer this once you have a lens port combination that is absolutely exact.

For the purpose of my calculations I have measured that my E-Mount camera is 27mm recessed inside the housing. This is important as it is needed to calculate the extension for the dome. If you are in a different format you need to measure this distance yourself.

Entrance Pupil to Housing Port

We have previously determined the entrance pupil from the lens mount and now we know how much this is recessed in the housing so we can calculate the required extension to reach the entrance pupil however thisassumes the domes are hemispheres which in most cases they are not.

Distance from Port → Entrance Pupil Distance from Lens Mount - Housing Recession Factor

Wide Angle Ports

Again we need a calliper to determine the depth of the port as those are not full hemispheres. I have access to the 180mm dome and I know that the port is actually 8.5cm tall from mount to glass edge because I measured it. Thismeans I need to add 25mm to the extension required.

Extension Required = Distance from Port +- Port Correction Factor

What about other brands?

The challenge with other brands is the lack of documentation however you can contact the design department to obtain information on the dome port they should not be a secret. The other challenge is the availability of extension rings. The Nauticam system has a level of precision of 5mm which is excellent however I am under the definite impression that they run their tests using in most cases steps of 10mm and using as first approach how the lens fits the port, they do not go and attempt to determine the entrance pupil.You can observe that because when you look at a specific port say the 180mm wide angle and you apply the suggested extensions in all cases the lens edge is flush with the extension.

In most cases this turns out to be accurate however there are some cases where wider lenses need to be more recessed and narrower lenses need to stick out more.

Fisheye Lenses

When you use a fisheye lens with a complete hemisphere dome port the calculations remain the same however it is a bit simpler to proceed without data. If your fisheye has a diagonal 180 degrees view and your extension is too long you will see vignette in the corners.

However if you push your fisheye lens closer to the glass you may be able to use a dome with a smaller field of view but the edge distortion will increase and so will chromatic aberrations.

Wrap Up

This article has shown that it is possible, with basic knowledge of trigonometry and access to lens, dome and camera design information to determine:

• How well a lens may work
• What is the minimum dome radius required to preserve the image quality
• What is the extension required
• How to find out the required field of view of your port

Without acquiring the actual lens camera or wide angle port. It is important to understand that if a lens is weak in air it won’t get better in water and in particular you need to appreciate that topside tests are not identical to use behind a dome that instead means working at very close focus well under one metre mostly around 30 to 50 cm. It may be worth it in some cases to rent a lens if available and take some tripod shots at close range. If you see really weak performance the lens may not be worth housing it at all.

I hope that this article allows you to have a more informed view of the key factors to look for in a lens that will ensure underwater performance is as good as it can be.

Methods to determine the appropriate dome port for a wide angle lens in an underwater housing - SHORT.pdf

Methods to determine the appropriate dome port for a wide angle lens in an underwater housing - SHORT.pdf

As a DIY Fiber Cable article was just posted, this seems like a good time to share this article on 3-D printing connectors for your DIY cables. The Connectors are really the heart of the cable, as the fiber is simply a manufactured item bought from a supplier. 

One of weak points of most of these DIY's is getting the right connectors. The solutions range from buying connectors (at about $10 a pop or $20 per cable), re-using connectors from old cables (which may require drilling them out and gluing fiber) to using random bits of off the shelf hardware which may have poor fit and finish. I've tried all of these solutions.

Early in 2023, I bought my first 3D Printer and have been making a bunch of Scuba/Camera related parts. One of my early projects was a set of custom designed connectors for Optical fiber strobe cables. I think these are at least as good as the OEM cables I've seen from Nauticam, Inon, etc. And it had the added benefit of being really fun to design, print, test, and refine. I've been actively diving these connectors all year as have friends I gave cables to. Collectively we have done a couple of hundred dives with good results.

If you have a 3D printer with some TPU and PETG or PLA material, you can print these out at a very low unit cost. You will need some M3x6mm nuts and bolts and 2mm thick fiber optic to complete. I suggest either 1-meter or 1.5-meter cables depending on your strobe arm configuration. 

I've just uploaded the design and STL print templates to the public sharing site Thingiverse:  https://www.thingiverse.com/thing:6134211 

Thingiverse Details:

Inon Style Optical Fiber Cable Connectors

https://www.thingiverse.com/thing:6134211

Make your own optical fiber cables using these connectors paired with 2mm fiber. I used both 613 multi-core fiber cables and cheap TosLink cables. The design assumes 2.2mm OD for the cables.

This design contains two styles of connectors: A 90deg elbow and 180deg straight connectors. The elbow part is printed with PETG. PLA will work but may not stand up as well to the elements. The actual connector parts are printed with TPU. These parts must be soft rubber, so no material substitutes are possible.

The 90deg Elbow part snaps together and is secured with two M3x6mm nuts/bolts. These nuts & bolts can be purchased from many sources like Amazon and are very low cost. (A set of M3 bolts with ~40 sets in several lengths is $10) The TPU connector and strain relief parts fit in the groves of the elbow. Thread the optical fiber through the TPU parts and align them into the elbow before screwing them together.

The TPU parts should be snug enough to hold the cable secure with no adhesive. If it is not secure, you can apply a small amount of silicone-based glue to the cable as you thread it into the TPU parts. Using glue may make it difficult to reuse the connectors should a cable get damaged.

Use the connectors in combinations that work for your camera rig. I like a 90deg connector on the top of my Nauticam housing and a 180deg connector on an Inon or Backscatter strobe. With a Retra strobe a 90deg connector will work better.

I have found these connectors to work well with a firm connection that is installed or removed with appropriate resistance.

DIY Fibre Optic cables

Like most members, when I bought my first system that used fibre optic cables, I paid for the ones that the dealers sell.

Reading various articles about fibre optics, I realised later that they were relatively easy to make and that DIY cables could cost a fraction of shop-bought. I gave it a go.

I thought it worth a write-up here on Waterpixels. And yes, they are really easy to make and are cheap.

The Cable

The best fibre I have found for strobe cables is called 613-core Fused Multi-core Simplex Cable, Polyethylene Jacket- MCQ-1000.  Bit of a mouthful!

A meter will cost about $7.50 and that should make at least two cables. A couple of years ago we coordinated an order between a group of forum members and bought 86 metres (!) from Industrial Fiber Optics in Tempe, Arizona. It was a bit of a shock when it arrived on a huge cable drum!

Cutting

The 613-core fibre is easy to cut using a sharp, box cutter-style blade (a Stanley knife to we Brits). Don’t be tempted (as I did to start with) to use a pair of scissors as that is likely to result in not quite a clean 90-degree angle. Although this will probably work fine for Manual initiation, TTL needs more accuracy and a scissor-cut can impact on the cable’s transmission quality for TTL purposes.

You can buy purpose-built fibre optic cable cutters but unless you are going into mass production, they are not really necessary.

Curling

If you really insist on having curly cables, cut to length and then curl the cable on a pencil and dip in hot water for a while. I found though that my shop-bought curly ones were a pain and lead to strained and tugged cables. Go with straight and feed them through the strobe arms.

Fittings

Various plugs (or “bushes”) are available for either or both ends of the cable. Inon make a double hole plug - available from Divervision for $1.95. Howshot make an “Adapter L bush” for the massive cost of $3.95. I use an Inon plug at the strobe end and a Howshot at the housing end.

None of these fittings need any complicated assembly, glue, heat, soldering or magic. Simply push the cable into a hole.  In the case of the Howshots, poke, bend and tighten a screw. Truly not rocket science.

In conclusion

I made a bunch of cables, they have done hundreds of dives and work like a charm.

One of the really neat things about DIY cables is that you can have any length you want - including creating an extra long one for off-housing work. If by chance they break, just recut at the break  - or just cut a new one.

The cost of a complete cable, less than $10. The sense of achievement, priceless.

Give it a go!

I installed my first Leak Sentinel vacuum valve, a V3, in my Subal ND800 housing in 2014. Over 700 dives, changes of camera housing and upgrades to the Sentinel system, I’ve moved through V4, V5 and now the newly available V6. As the slogan goes, I’d never leave home without it. Why?

The Sentinel provides a unique extra level of security and reassurance to an underwater camera and has saved me from my own stupidity a couple of times…… So what is it?

The Leak Sentinel is a small valve which screws into a spare bulkhead on an underwater camera housing to monitor for leaks even before the housing goes into water.

A small hand-pump of the type used in the Vacuvin wine bottle corks then draws the air through the valve and out of the housing. (A small battery-operated pump is also available). This creates a vacuum indicated on the Sentinel by a green, “Good to Go”, blinking LED light. If the housing has not sealed properly because of a fault or, more likely user-error, the valve warning light will flash green/red or red indicating a problem.

Vacuum valves are great devices particularly to help avoid user-errors and, more importantly, warn of an issue before the housing gets wet. It is this feature which makes them even more valuable than a housing leak detector which only works when water is already in the housing.

Given the cost of the housing and its contents, installing one of these handy leak warning devices is money extremely well spent. I would argue it is one of the two best investments I’ve made in my system. (the other being a 45-degree viewfinder!)

The Leak Sentinel system is simple to install. The valve is screwed into an empty bulkhead on the housing so that the blinking warning light is visible when diving. In earlier models (V1 to V4) the battery was part of the Sentinel’s valve assembly. In the V5 “XB” model the battery was fitted on a printed circuit board fitted inside the housing with a wire connection to the valve. This avoided the need to disassemble the valve to change battery.

The V6 has just been released. Like the V5, the battery fits inside the housing. However, the cable is now fitted permanently to the battery circuit board and a connector has been added (see photo) linking the battery to the valve assembly. This is a big improvement as removing the V5 required disconnecting the wires at the printed circuit board – which could be problematic.

In addition, gone is the square of Velcro which was supplied to hold the printed circuit board to the top of the housing. Now there’s a magnet! This should make battery changes even easier.

Like the V4 and V5, once a vacuum is established and the LED stays green for a reasonable length of time (I usually wait an hour), the Sentinel can be switched off by pressing the LED and left until dive time. This saves battery life. Switch it back on pre-dive and the green, Good-To-Go LED should reappear and blink steadily.

The Sentinel electronics allow for an element of temperature variation. It will cope for example if the camera is setup in the housing in an air-conditioned room – and then moved into a higher ambient temperature before diving.

The system uses an easily available and inexpensive CR2032 battery. Battery life is certainly into the dozens of dives and many hours.

On the very rare occasion when I’ve had a question, the Leak Sentinel’s producer, Miso Milivojevic of Vividhousings, has being unfailingly helpful at finding a solution in response to my emails.

So, easy to install, easy to maintain and relatively inexpensive…. is it worth installing one on your system? No question. Who doesn’t want to reduce the risks of a flood and enjoy the additional reassurance a vacuum valve provides. Never leave home without one.