Chris Ross

It's not so much the cameras but the lenses - compare an Olympus 60mm macro with a Canon RF100mm macro. 185 grams vs 730 grams, 82 x 56mm vs 149 x 82mm and less than half the price. Or the Olympus 12-40 f2.8 vs the Canon 24-70 f2.8 - 382 grams vs 900 grams and the Olympus is 40% of the price. The olympus lenses also generally focus closer with more magnification (apart from macro lenses) and will work in smaller domes. On the macro front both are 1:1, however with the 2x crop factor a 1:1 lens fills the frame with a subject half the size on Olympus, so less need for diopters.

Have to say I agree.

OM systems has been pretty good at issuing firmware updates for their cameras, bringing new features to the body. A lot of new features rely on more powerful processors and are only available on the latest models. They are also bring features from top line models down to models like the OM-3 fairly quickly.

welcome aboard, good to have another Sydney diver join up!

The biggest issue for Fuji is the limited lens lineup I think with only a handful suitable to use underwater. I really hope m43 keeps going, the small lenses are great, relatively inexpensive and very easy to travel with and it seems to be the camera of choice for macro shooting on land, I follow quite a few people using them macro shooting of bugs etc.

There's also posts on the forum about using the Sony 2x with the 8-15 along with the metabones adapter on the forum. This gives full diagonal fisheye through to about the equivalent of a 14mm lens, very flexible arrangement. I have one adapted to an OM-1 and it provides great flexibility and the optics are excellent. With this setup you have camera - Sony 2x - Metabones - lens. Do you print your own gears or do you get someone to print them for you? One of our forum members, @Gudge has printed zoom gears for me, he's based in Perth if you need someone to print them. He may have a design already.

Nuidbranch names do change quite often and also it is best to use the scientific name when searching as the common name can be shared by a number of species. Google search the scientific name to see if what comes up matches your pic.

not certain about it and the OM-3 certainly seems to tout the subject recognition.

I have good experience with the OM-1, it locks on pretty well, the only thing I notice is that it sometimes won't focus on a close subject as it can see the background through it, but dealing with that becomes instinctive. I can't compare to the OM-5II/3 as I haven't used them but they are said to share the OM-1 AF.

No unfortunately don't have one.

nice shots, my MFO arrives soon, agree the shore dive exits can get a little rough at times. Didn't know you were in town, are you visiting or based here?

There was a thread on here specifically recommending against stacking the MFO-1 and any of the Nauticam close up lenses as they both have the air-water interfaces and would double correct. The Fantasea lens won't have that correction, though it is quite a low power lens compared to the CMC-1 and 2 lenses. If the MFO-1 has a front thread you could try stacking and see if you like the results seeing as you already have the lens. You could even try it in a tub shooting a flat target to see what the quality was like.

There are lots of position on the dial on your UWT trigger as there are lots of ways to do TTL and each camera manufacturer has it's own way of doing it and requires a different trigger board and each strobe manufacturer has adopted different timing etc for their TTL as there are a number of ways to do this and each style of TTL has its own position on the dial.. Pavel had a post on this a while back. This is just on getting TTL to work before worrying about implementing HSS. This is made more difficult as in general it is done of fibre optics and with the possible exception of Olympus RC1 there is no dedicated handshake like you would get with a Nikon camera communicating to a Nikon strobe. Add to this, the TTL protocols are reverse engineered to work over fibre optics. Your specific question I think is best answered by Pavel, I would send him a PM. On your question, a black band means it is not syncing properly, there could be any number of reasons for this. If you look at the instructions for the latest current UWT trigger here: Google Docs#11071-HSS-SONY-A7-June2024.pdf you will see that Marelux has a separate dial position including HSS, so it appears it uses different protocols. I would suggest that given you can use up to 1/400 it would seem, that this is better than your camera's 1/160 and just work within that limitation. Controlling output in HSS can be done by changing shutter speed, aperture and ISO. so to get your exposure right you can juggle all three of these. As you increase shutter speed the exposure from HSS will reduce as it acts like a continuous light source. Probably the best way to proceed is to start with your current settings and adjust the shutter speed up and ISO up to keep the background exposure constant and do some test shots.

Davide has given you some good basic pointers to get started, while I'm no video shooter, I've picked up a few things, playing with a little footage. Firstly the amount of adjustment you can make tends to be more limited than what you might be used to on stills, depending on what codec you used. Second getting close on white balance out of camera is going to make your life easier, smaller shifts are easier to deal with and you are less likely to get "lost" along the way and end up with a messy looking clip.

Yeah I saw that, a nice solution, I'm thinking for people who aren't as comfortable spot welding battery packs together and if they have the space installing the same batteries in a holder that would be a good solution as you probably don't need any balancing for the batteries as you can pull them out and charge them in a dedicated 18350 charger, so you don't have to be concerned about getting them all fully charged.

Congratulations Ross, a great image.

I think the capacity would be a little on the low side with two, 11 W-hr which is less than the on board battery, but it's not essential I guess.

I think the benefit of using some type of holder is you don't have to worry about battery management for charging. I also found this one and 18350 which is 35mm long 18 dia, might be able to do something with them, but you'd need four of them. Ali express has holders . https://www.liteshop.com.au/content/nitecore-nl1816r-1600mah-usb-c-rechargeable-battery/?gad_source=1&gad_campaignid=17182817440&gclid=CjwKCAjw2brFBhBOEiwAVJX5GD8NqXpZ7sSwOyl6OeguSdGD1zIFkTQVEi74Q9Cvz1gm6ajRUxZmeRoCXxoQAvD_BwE

Yes that's at 5V from an Iphone type charger, wondering if it might work better with two batteries in series as the readily available batteries are 3.7V. Did you check afterwards did it draw power from the onboard battery or from the charger, the battery reading after pulling the plug will tell you? Your housing it seems has space for the mini flash and if so I would think you could readily fit two 18500 batteries in there and if the battery holder is not too big that should also fit and that's effectively a second battery. You probably won't have the issue mentioned in the video if you just use batteries without the voltage step up. The 18500 batteries are short 18650s and are 50mm long. It seems like that option could be quite doable with minimal work apart from attaching a USB cable to the battery carrier and it looks like there is enough space where the flash trigger would go.

Welcome aboard, hope you find the forums useful.

I would also add I found this video talking about using an external battery to power a camera. Basically the issue is the voltage step up keeps the voltage stable at the 8.4-9V so the battery charge indicator always shows 100%. As the battery depletes eventually the battery protection circuit cuts in (assuming you have protected batteries) and shuts the camera off. There is no low battery warning! The battery voltage can then recover after the camera powers down and the camera can re-start and it can cycle like this for a while apparently. The video says that this destroyed the circuit board in the camera after a few cycles. So you need to be extra aware of the power level in the auxiliary battery with type of system. I see though he is using a very compact little step-up box to get the right voltage.

There's three issues to deal with and the voltage delivered is just one of them. First can you get a battery to fit and is what you can fit a decent enough capacity. Second How does the camera react when plugged in. Some cameras only accept charge when the camera is turned off, newer ones will draw from both USB-c plug and the onboard battery. On getting batteries to fit, the 18650 is 18mm dia x 65mm long which is probably a Squeeze. You can get 18500 batteries which in the high capacity version might fit. For your GH5 a twin 18500 battery holder might fit like this one: Battery holder The 18500 is 18mm dia x 50mm long. If you sourced two 18500 cells and wired the box so it was in series maybe you could use that and they seem to have a 2040 mA-hr version available. and that would have 15.1 W-hr available which is just a little more than the standard GH5 battery at about 13.4 W-hr. You could remove them from the holder and charge them in a Li-ion battery charger. The advantage of the battery holder is you can pull the batteries out and charge them in a regular charger. Whether that is worth doing depends on how the GH5 behaves when plugged in via the USB port, the GH5-II it seems will power up through the USB-port but needs a battery installed, but it seems the GH5 only allows charging of the battery when camera is off. It is said to need at least 9V though and the two 18650 will deliver 7.4V. Using a dummy battery could also be an option, but to be worthwhile you would need more capacity in your extra battery, so probably 4 18500 cells but voltage is a little low at 7.4V. Apparently the GH5 batteries are chipped and if the voltage is too low it assumes you are using an unchipped battery and won't power up, but if it's 8,4V or higher it will assume you are using an AC adapter with dummy battery, but much higher than 9 and it will maybe fry the camera. You could use a regulated step up converter, but that is starting to complicate things and you would be running out of space. The step up converter needs to supply 9V at 3Amps to keeps things stable.

I just upgraded from Z240 to Retras, the big thing I noticed was backscatter control was much better with the reduction rings installed compared to the Z240. Regarding the AOI strobes you mention macro will be fine with either I think, but I expect they may be a little under powered for wide angle particularly with a full frame camera. Does AOI offer reduction rings? I think I would want that for macro work. Regarding the Retras, seems they only offer the Pro Max II and the Maxi is on pre-order. I got a pair of the Pure model before they discontinued. They are quite an expensive option, though they are very well made and the light and the control of the light is excellent.

A lot of discussion already, the simple fact is that a 6"dome is really too small for a 15mm rectilinear lens. I would also mention that Seafrogs will get your camera underwater but they use generic extensions and often don't have the optimum spacings in their port chart, they will fit and take photos and generally won't vignette but are not always in the optimum position. For example the R5 plus 8"dome is said to work with 16-35 and 24 105 lenses(with EF adapter) and lenses. Nauticam uses 50mm extension for the 16-35 and 70mm for the 24-105. Regarding dome port theory this article is very good and includes a calculator to see where dome port virtual image is located. Understanding Flat Port and Dome Port TheoryOne of the key features of underwater photography is the dome port. Despite it's ubiquity, it's effects are largely misunderstood or at the very least, poorly explained. In this post I'm going to ta You asked about hyperfocal distance, this really isn't a thing underwater with dome ports. The lens is focusing on the virtual image very close to the port and is close to its minimum focus distance. To calculate minimum focus distance, UW you can make use of the calculator linked above, as follows: calculate how far the minimum focus distance is beyond the dome Set the dome size and aperture. The aperture is the size of the entrance pupil so set to minimum Change the object distance until the virtual distance = the minimum focus distance from the dome surface you calculated. You asked if it's better to have too much or too little extension. probably doesn't matter much, one way gives barrel distortion and the other pincushion. 'However too much extension causes vignetting as the dome shades start to show in picture. Regarding the 14-35 lens and your calculations, the critical things to estimate are the radius of your dome and the entrance pupil location, you didn't mention how you came up with those figures. You can calculate the radius from dome diameter and height with circular segment formula, but generally you need to measure the location of the entrance pupil. You want to use the entrance pupil location at the widest setting. I think at this stage and especially in a 6"dome you won't make a material difference in your photos by investing in another lens. Lots of things contribute to sharpness underwater and it's not all about the lens used though that can make a difference. On the subject of unsharpness, there are a few things to consider, what aperture were you using? I would think you should use f11-16, tending more towards f16 due to the small dome. How close were you? The first rule of UW photography is get close and if you think you are close enough, get closer still. Secondly you are using natural light it seems and while you can take nice shots in natural light, UW shots lack generally lack contrast. The third shot with divers for example looks very milky - this is because they are too far away and you are shooting into the light. If you were using strobes you could drop the shutter speed to darken the background water and illuminate the subject mainly with strobe light - of course strobe range is very limited and you want all your main subjects at a similar distance so you can illuminate them. Getting this right gives the impression of sharpness from contrast. In the meantime when shooting natural light, be aware of where the light is coming from, having it behind you tends to work best , UW the light doesn't get under overhangs etc and they come out black and the shadow side of fish for example tends to be very dark. On the topic of split shots, without strobes the biggest challenge is the wide brightness range. To focus in this situation remember the virtual image is very close and depth of field extends behind the focal plane more than the front. So focus on the UW part and have it quite close to you and use f22, you really need to be in relatively shallow water for it to work well. It is particularly challenging with a small dome as the virtual image is very close and optically the water line is very thick with small domes, not to mention that water movement makes it challenging to hold the split line where you want it. On the question of your calculations, it is nice to be able to do them to confirm things, however practically speaking are you able to obtain extension tubes close to what you have calculated? Sea Frogs only has a rather limited range available.

Video AF tends to be more problematic and I seem to recall that video AF does not work at all with the MC-11, this post mentions it: Metabones say theirs works but says: "Continuous video AF is functional in Advanced mode only but performance may be unsatisfactory." That same post says the adapter provides flawless AF on stills and video with the tokina adapter with a Sony A1 and Canon 8-15 lens. Reading through that thread may help you.