Chris Ross

Looks like a giant moray, if it is it should have a dark patch on the gill opening which seems to be behind the coral in this shot. DO you have other pics? There doesn't seem to be too many species which look similar to the giant moray you could point to as a maybe.

Some info here on PAL vs NTSC mostly seems to revolve around flicker under mains powered artificial light: https://www.reddit.com/r/videography/comments/s6j8cb/pal_vs_ntsc_for_internet_videos/ As for WB as I understand things colour grading has limited scope to correct colour casts and works best if you are close, unless you are shooting RAW video. In any case getting it right out of camera is probably a lot less work in processing and less likely to cause issues in the final clips.

Seems to be roughly double the energy input calculating the Ws for each full power flash the same way compared to the Retra flash ProMax. I seem to recall Retra used to quote a 130° coverage for the circular tube models, the maxi has 160° so won't be double the light on the subject. Changing the field covered from 130 to 160° decreases illuminance in lux( that is light intesity on the subject) by about 70%.

The logical suggestion is a WWL 1/1B however using a bayonet system with these lenses needs the nauticam bayonet-M67 adapter to fit on the AOI port - it doesn't fit on all ports if the rim is too thick. Seems like it would be better to use this with a 14-42 if mounting arrangements suited you. The WWL-C doesn't give full 130 deg with the 12-50 but you could use it with a Panasonic 12-32, but only way to mount this one is if the Nauticam bayonet adapter fits the AOI port. The AOI is an option as well you and have the choice of a PC or glass front dome and they sell a quick release setup as well as a buoyancy collar - it says the collar makes the PC dome +ve UW.

probably a good idea as long as they provide a decent area to charge everything.

It is established that the Nauticam manual flash trigger will sync at higher shutter speeds than the published sync speed. The key is that the strobe or trigger is triggered by the x-sync contacts which are basically an electro-mechanical switch incorporated into the shutter. There are no electronics that tell the camera that a flash is attached so the camera doesn't lock out the higher shutter speeds, it just flashes when the X-sync contacts close momentarily when the shutter is released. Whether the AOI trigger also allows higher shutter speeds depends upon the triggering circuit used - if the camera recognises it as a flash it will limit the camera to 1/250. It seems the EM-10 MkIV is a special case among Olympus cameras as it has a built in pop up flash and only that will sync at 1/250. Even hot shoe Olympus flash units that happily sync at 1/250 on other models like the EM-5 and EM-1 series will be limited to 1/200 on this model. It's only when you get to the higher end models that 1/250 sync is universal.

Interesting - it seems that the AOI trigger does properly support the RC mode based on what you have said. It would be so much easier if you could use the pop-up flash for triggering as it could do all 3 modes reasonably seamlessly at the cost of a little battery life - in manual setting the flash to 1/64 power triggers things reliably in my experience and uses very little battery power.

The thing with macro lenses behind flat ports is that the aberration increases continuously from center to edges as the angle the light rays are coming in gets progressively greater as the angle of view increases, so it's a progression, only in the very center of the port are the light rays perpendicular. However out at the rule of thirds points where you might place something important to your composition, the rays are at an angle and you are about half way out to the edge. If you photograph a test chart on land you will see something similar a slight degradation in quality that gets progressively worse towards the corners, but it is going to be hard to spot that in a regular photograph - It's only when the aberrations reach a certain level that they are obvious. UW the port and lens aberrations add together. The other thing that is claimed is reduced hunting - apparently due to compressed focal range. I would also think that removing flat port aberrations can only help focus is easier to find on a sharp lens. It sounds interesting for sure, But I think we might need to wait for some high resolution test shots to see if any improvements are enough to convince you that you need one! 😂

The issue with trouble shooting flash operation is that the camera and external strobe have no idea about what each other is doing. The UW strobe merely responds by triggering in repsonse to a light pulse. The issue is that each side needs to be set to the right setting to get results. The Olympus RC control gets around that as the camera communicates with the strobe via light pulses. First of all the Olympus RC protocol can't be used to trigger strobes that are not set up for it. Both the camera and strobe need to be in RC mode. You could use that if you were trying to use TTL with your setup. It sounds like you might be trying to use TTL. If you are prepared to use manual control the X-sync speed is reported to be 1/250 but only with the built in flash it seems. What are you using to trigger the flash? It is reported that using the Nauticam manual trigger bypasses the shutter speed limits. TTL triggers can do this. The built in flash should work in both manual and TTL (not RC) up to the published 1/250 limit. It is 1/200 limit for external flash units which may include a TTL trigger. You should be able to check all of this on the camera alone to establish your max sync speed. Set the camera to manual exposure , the flash to auto and see what SS you can reach in that. Then repeat with camera in manual and flash set to manual to see what SS you can get to with the built in flash.

As I understand things, the issue this deals with is the air-water interface of the flat port, where away from the very centre light rays are refracted through the front port glass which degrades the image. It is already documented that short macro lenses suffer towards the edges due to this, the situation though is a gradual improvement as each light ray is refracted less and less as the centre is approached so it is only the very centre where light rays are not refracted at all that does not suffer some degradation. Longer macro lenses also have this abberation in flat ports, however it is just reduced in magnitude, compared to a short macro lens - not eliminated In air it is certainly true that adding glass degrades images by some amount, however in the case of the MFO it is correcting the issues caused by the air water interface of the flat port. I'm not sure how this is done, perhaps it induces an equal and opposite abberation that is cancelled out as the ray passes through the port glass?? Hopefully this is clearly explained.

Suggest you look at the manual for the R50, From what I can see this is a camera limitation as it only has one control dial - so in Manual, the front dial sets SS and aperture you need to press one button to allow the same front dial to change aperture. You also have to sight and compose using the rear screen as there is no viewfinder. The G7XIII has a control dial and a control for SS/aperture, the Nauticam housing can control both, though they are not quite as ergonomic the big Nauticam housings to access. You can download the housing manual from the Nauticam website, there is a link on each housings page to do this. Likewise you can download camera manuals to check functionality. The Olympus/OM system cameras have all the features you would expect to find in a DSLR or ca-nikon type mirrorless camera. Two programmable dials to control SS/aperture and ISO/exp comp.. The housings are a huge amount smaller but the lenses and domes/ports are significantly smaller than full frame equivalents. You can use the fisheye lens in a 4"dome port and the port for the 60mm macro is quite small. The housings operate the same way that the big DSLR housings do at least for the OM-1 with ergonomic access to SS/aperture, the OM-5 is a bit smaller but the dials for ss/aperture are a little harder to access. Here is a shot showing the OM-1 with it's housing, 60mm macro port and a 4"zen dome and the Panasonic 8mm fisheye plus 12"ruler for scale: The Isotta housing would be slightly smaller. You could probably get away with the very compact light (345 gr) INON S-220s with this rig, they are very close to the same power as my Z-240s. You can do this as you can shoot at f8 for wide maybe f10-11 for macro. What subjects do you typically shoot - macro? a lot of reef scenics?

First thing to check is if the trigger or mini flash is firing at 1/250. Also confirm you are in manual flash on the camera. When you say they won't fire - do you mean they won't fire at all or that they no longer sync?

It's basically a slightly larger version of what you would have with a Canon G7X, fixed port that uses the Canon 18-45 kit lens with either a WWL or a diopter for macro. If these fit the with what you like to shoot and are aware of the limitations, then potentially a good option. Assume you are aware it's not expandable beyond this. Another mid range option might something like a OM system OM-5 perhaps in the Isotta housing - small and compact you could have that the macro port for the 50mm macro and a small dome (4.5") for the 8mm fisheye. This would easily fit in a carry-on size backpack and be quite light. Alternately you could use the OM-1, for longer battery life.

Assuming the price in France includes VAT, that explains a good portion of the difference. Technically I would guess you are supposed to declare goods coming into the country and pay the VAT upon return as any of these items would exceed the duty-free allowance for travelers. In addition to the warranty issues, you need to consider the policies of the local distributors for the cameras in question. For example I understand that Nikon USA won't even do paid work on a non-US model camera, at least that was the case a few years back. The issues are that warranty and support aren't free, the margin in country pays for the support infrastructure. In some cases there are excessive margins, but that is steadily eroding due to the ablity to buy goods from overseas sources and online sales in country.

Thinking about that maybe using the 90 mm macro behind a small dome might be enough? Losing the flat port magnification you would be equivalent to maybe about a 70mm lens behind a flat port.

No reason you couldn't do it, apart from being potentially unwieldy. Probably be fine getting on and off the boat in calm seas, also consider if currents might be an issue. I would also consider that if you could double your light output by adding an extra flash, that is one stop of light. Your might get maybe 1/2 - 2/3 stop more light with the extra flash. Depending on where you are on shutter speed you could achieve more or less the same results with one stop more on ISO. Maybe try something like opening up by 1/3 stop and 1/3 stop higher ISO?

Seems like a massive leap going to a phone housing, you'll not have strobe light as you know. Have you considered going part way, something like a Canon G7X would fit into something a lot smaller and be reasonably versatile particularly for wide angle. Macro not so much, certainly do-able and better in terms of small subjects compared to what a phone could do. You could get away with smaller strobes like the INON S-220, possibly even a single strobe. I would kind of think of a phone housing as producing a record shot, not to say it can't take some really nice images. Whether you're happy really depends on your expectations for your images.

I see the new maxi output is quoted in GN, while the circular tube strobes have power listed in Ws. I would be interested to know how the maxi compares to the output of the circular tube strobes.

I think there are a number of issues you are facing - first adapted lenses and macro are always going to be a problem, the second a lot of zooms are slow on the long end and less light means AF suffers generally. Plus kit lenses generally don't have the best AF a company has to offer. Extension tubes may work, but you are back to the same situation you have when using a diopter, the focal range is relatively limited. Adapters like the Nikon FTZ or Canon ef-R are probably less impacted and there are a number of EF or F mount short macros that may work well enough? Generally short primes are pretty snappy to focus. On my OM-1 the 30mm Panasonic is noticably snappier than the 60mm macro up to at least 0.5x. An extension tube on a fast prime may work as well??? Seems like there's compromises to be made, perhaps one is to accept taking video in a crop mode with a lens that is fast to AF but not so good at min focus or perhaps a lens that only reaches 0.5x? The difficulty in focusing seems to go as you increase magnification, particularly beyond 0.5x. I'm wondering if the Canon STM lenses that go to 0.5x might do well enough for you under this scenario? Just some random thoughts.

Depends on the lens in question, I know the Nauticam 180mm dome has a max angle of view of a 16mm lens with exit pupil positioned properly as the dome is not a full hemisphere. This means the exit pupil needs to sit forward of the optimum spot to avoid vignetting. The marelux has a slightly bigger throat which helps with positioning but not sure if it can be placed 100% correct. The Sigma lens you mention has a long minimum focus distance (28cm) while some newer lenses focus a lot closer like the 17-28 f2.8 tamron which focuses down to 19cm. This means it works well in smaller ports. There are lots of posts on the forum discussing that the new Sony wide zooms and the Tamron 17-28 among others will work well in a 180mm dome. I'm sure some will chime in with direct experience. I don't recall the Lens you currently have being among them. You could buy the 17-28 tamron and the 180mm port for less than the price of the 230mm port alone and get a smaller lighter package that is easier to travel with. Probably the more important question though is if a 14-17mm rectilinear wide lens is the right lens for what you want to shoot. Fisheyes are very popular for reef scenics and wet optics with the WWL are popular for CFWA and make for a compact easy to shoot and flexible setup.

It depends on how much buoyancy you'll be adding. In general you want the buoyancy components up high as they will want to turn to be there anyway even if the rig is overall neutral and the classic way to do this is buoyancy on the strobe arms. But if the buoyancy you add is too high you'll have a significant torque trying to prevent you from rotating the camera to point up. I think something 500-600 gr of buoyancy on the arms is fine, i have this on my regular rig and I don't notice the torque. On my newer setup using the Canon 8-15 on the OM-1 to get neutral I needed 2.2 kg of buoyancy and tried it with two 670 gr arms and two 210 gr arms and twisting it was quite difficult and I ended up removing the two 210 gr arms and dived it about 450gr negative. The reason for the torque is twofold - the amount of buoyancy and the arms being quite long it was placed a long way from the centre of mass so a strong lever. I am thinking of adding about 400 gr of buoyancy to the base plate. So just weigh your rig on a luggage scale in water and come back for more specific suggestions. What to do will depend on how much buoyancy you need to get close to neutral

You don't need an app to do that for you, just process a copy and copy it in as a new layer and mask it, simple enough to do in Photoshop.

Thanks Dave, The point is it makes comparing the fields you get from various lenses easier, particularly if you are comparing a rectilinear to a fisheye where the focal length is not a good guide at all. The purpose of providing a field of view is to help determine what sized objects you can fit within that field. Generally what you can fit is defined by the width of the long axis - you don't frame subjects diagonally in general. The issue you have is that the the barrel distortion of the fisheye and WWL is not linear, the degrees of field covered per mm of sensor increases as you get further from the sensor - the corners are stretched. This means that as you zoom in you get narrower fields than you might expect. The example I provided above of an 8-15 lens on m43 , from looking at focal lengths it seems like it is a 2x zoom lens, but it's actually like a 6 -28mm lens or a 4x zoom and replaces a fisheye and a 7-14 rectilinear in horizontal field coverage. Back to the original question, the 10-17 was very popular because it zoomed from a fisheye all the way to a 22mm rectilinear lens, about a 3.5x zoom ratio based on horizontal field. The only full frame match for that lens currently is an FCP which is an expensive, heavy option. The WWL-C has a similar 3x zoom range but shifted to the long end and missing the fisheye end. AN 8-15 with an added 1.4x gives about a 2.5x zoom ratio but lacks the reach of the WWL-C and Tokina 10-17. The other factor with the fisheye is the barrel distortion which brings your subject forward in the frame - it appears bigger and fatter - so for reef scenics it's really unbeatable. SO the choice to replace a Tokina 10-17 is if you mostly used the 10-14 range of that lens, an 8-15 with a 1.4x will replace that very well, but if you were mostly using the long end of the 10-17 the the WWL-C with 24-50 is potentially a better choice. If you do both reef scenics and CFWA then you might want both.