Chris Ross

It's not so much the software, it's physics. By the time the part that is further away comes into focus, the closer part is badly out of focus and partly obstructing being able to see the further part. They provide two main stack methods (3 in total) One is better at avoiding the blurs of foreground objects the other better at avoiding haloes around the perimeter of the object. You can use one method to re-touch the stack made by the other method. But it has limitations and if subject parts are too far apart (in distance to the camera) it eventually becomes too hard to re-touch. Then there's the garbage in garbage out problem, setting up the stack can be challenging and it's easy to mistake which object you want to place in focus for the starting point of the stack. and it can be hard to detect if you captured everything in fine focus just looking at the small screen, particularly if your vision in not 20/20.

Yes, Helicon, it does a good job but has its limitations. First it's only as good as the frames you feed, second you need to work out how to re-touch , any crossing parts of the subjects at different distances will generate haloes, sometimes fixable in Helicon, sometimes requires cloning in photoshop.

don't say I didn't warn you. I have enough issues on land. What sort of tripod do you propose to use? The stacking software is good, but it has a steep poorly documented learning curve.

Don't believe so, this is hotshoe, there are 21 tiny contacts across the shoe, google probelms with Sony hotshoe and you'll get lots of hits.

First your housing floating, I always find positive housings to be annoying to use . You can get adjustable float arms from Kraken that allow you to get the housing perfectly neutral so it stays where you let go of it. Might be worth thinking about. Regarding cropping - do you crop as you can't get close enough or do you run out of magnification? The G5X covers 21x18mm field at max magnification and 67mm working distance with the CMC-2 The OM-1 covers 17 x 13mm at 1:1 with about 80mm working distance The Sont A7C covers 26 x 17mm at 1.4x and 90mm working distance So the Olympus 60mm gets more magnification on the sensor covering a smaller area at the same working distance as the Sony A7CR with the new 100mm macro. AF and finding subjects is easier with a proper macro lens compared to a zoom with a diopter. On the issue of latest models, yes there is a bit of FOMO, but from an image quality perspective, the improvements are incremental these days, comparing sensors from 15 plus years ago there are big advances but in the last 10 years improvements have come in readout speeds, computational photography and other aspects, rather than image quality measures. Improvements in noise and dynamic range are very much incremental, they are not non-existent but IMO not enough to choose one system over the other. By the sounds of your requirements, a macro is really what you need, many domes options allow you to get close and up 0.3x magnification, but the dome gets in the way for example trying to shoot a fish sitting on the bottom you have to shoot from above. If you are interested to look my website has a lot of UW images and there are quite a few fish of various types, you could look at this folder, all images are OM-1 with 60mm macro and select images with the MFO3. Australian Natural Images

It’s going to depend on how close you can get to your 1cm goby. A 100mm macro lens will do it, however it will only take up 1/3 of a full frame sensor horizontally. Then the 0.8m fish will have a lot if water between you and the subject, challenging strobe power and increasing chance of backscatter and reducing resolution. The MFO-3 will help , but has a limitation that its max focus distance is about 1.5m away. Different lenses will have different fields at this distance. I shoot with the OM-1 and 60mm macro, a fish about 700mm long fills the frame at max focus for the 60mm macro/MFO3 combination. I posted a thread on using this combo a while ago now: The trumpetfish in the photo from this post is about 500-600mm long and the frame is slightly cropped, so it looks like it will scrape in for your 0.8m fish requirement. The Olympus is certainly a smaller lighter option in Nauticam compared to full frame housings. It has 1/250 sync speed and can get 1/400 using the Nauticam manual trigger. You asked about gobies, this is a whip coral goby from Lembeh, OM-1 with 60mm macro, it's probably about 70% of the frame so some cropping, certainly could have gotten closer to this one. Certainly it's a decent option, some cropping is possible if photo is sharply focused to start with It will be lighter than most full frame options, though the Sony A7C will be a smaller housing I think - by a little bit. I get in and out over the rocks with some swell most of the time at my local dive site in Sydney and it's relatively easy to handle.

I think these days modern sensors are so good as long as you don't badly clip your image it doesn't matter , many sensors are ISO invariant and tweaking up exposure is no different to raising ISO in camera. Where it does help is in judging you haven't had too much flash as increasing exposure in post brings up flash as well and you wouldn't see it necessarily when reviewing the image when UW. But again if you have a histogram like shown above in my post you are not blocking shadows or blowing highlights and in fact you are only using 60-70% of the available dynamic range, so a high dynamic range camera does nothing for you. Stretching this histogram out with a levels adjustments maps the brightest pixel to just below clipping and dimmest pixel to just above blocking up and the contrast comes up and image is 90% of the way to being the finished product. So underwater all you do is expose to approximately centre the histogram and don't overdo the flash. What is happening is the strobe is not really brightening up your subject but adds enough reds that you can successfully pull the colours up and get a decent white balance. So in effect it's an ambient light shot with some warm colours added into the mix which enables you to achieve a satisfactory white balance when you adjust everything. Forget about balancing WB on the water vs the subject, you are not going to achieve deep tropical blues, but it will look OK. The other thing is that you'll only light up a 4m wide section of wreck or so at most with your strobes on the best of days so you are effectively shooting ambient light and colouring up some foreground objects with the strobes.

If you are proposing to do this UW - good luck!, I do a lot of focus stacking macro on land and anything but the stillest condition will make it near impossible, then your strobes need to keep up and there will be limitations on how fast you can shoot. You need to solidly mount your camera then rack it in and out to get the near point in focus then guess how many frames you need and give it a try and then check that the last the frame gets the most distant part you want in focus. Then you do all that and get home and find that you missed on getting the closest bit in focus as it was another part of the object that was actually closest and you go back and try again. I use an external monitor and magnify the image 2x on it to check the focus point for the start of the stack and again the check I got full coverage. Underwater - no thanks I'm not that much of a glutton for punishment.

I would suggest that these days there is little to pick between sensors in UW cameras you can either have a 20-30MP FF or a higher pixel count in the 45-60 MP range. Pick your poison in MP count then look rather to other features like flash sync speed, and the range of available lenses as well as housing support from various vendors. Also important is battery life, can it charge over USB through a bulkhead? what is flash trigger support like, all practical things that make life easier living with an UW housing. If you are looking at Nikon vs Sony in Nauticam that means N120 ports for Nikon and N100 ports for Sony. Practically speaking the N120 port range is not as good as N120 and you can end up needing an N100-N120 adapter (not cheap for Nauticam - but then again neither are their N120 extension tubes these days. In Isotta they both use N120 ports. Personally I'm not a fan of the Sony flash hotshoe it's a known weak point with lots of fine contacts which give connection trouble periodically, there have been a few people on here having issues with their hotshoe as I recall. Beware of paralysis by analysis though - just setup a costs spreadsheet to get what the lens types you want to use housed and UW and compare costs.

The argument here is you need high ISO as you are relying more on ambient light - basically the strobes are turned down to avoid blowing out the water. The real solution to this flat low contrast image is to set your black and white points - here is the histogram of an under flashed ambient light image: and here is is the adjustment in a levels tool: Now the difference this makes is quite significant, this is just a throwaway shot, but it is under flashed in murky water and it shows what happens when you set you white and black points properly- the LH side is out of camera, the RHS only has levels adjusted and shadows boosted a little: There's more that could done to fine tune things, a standard curves tweak, a bit of fine tuning the WB, brightness, etc, but what we are doing with this shot is compensating for the low dynamic range in the scene. The time taken to do this is way less than explaining what has been done, you just grab the white and black points on the histogram and drag them in. Higher dynamic range will make no difference at all to what is going on. It's not that you don't get the benefit of high dynamic range - it's that you don't need this benefit. As an aside you can also do your colour balancing with this tool by adjusting the black/white points on each individual channel.

If you stay within the Nauticam eco-system, this is mostly true however there are some examples I can quote: First a Sydney diver using a D850 wanted to downsize, they went I think with a Z5 camera. The Nauticam housing was the same size and weight as the Seacam for the D850, however the Isotta housing gave significant size and weight savings as it is much more compact in the way it is laid out. Second as recently discussed on here the Nauticam Z5II/Z6III housing is significantly smaller and also cheaper than the other Z series housings. The first Nauticam Nikon(and Canon )mirrorless housings were a lot larger partly as the set the camera back further in the housing by the thickness of Z-F converter so the F mount lenses and their zoom/focus gears would work with the same extensions as they did with the F mount cameras/housings. The new style housings accomplish this by using a Z-F adapter with it's own zoom gear so that the F mount lens zoom gears will work and you don't need to buy new ones. You still have the large ports and extension rings etc and the big lenses but the housing can be made smaller.

As I recall Nauticam stated that they used the 28-70 kit lenses from Ca-nikon as they had the required entrance pupil size and that faster f2.8 zooms wouldn't work because of their larger entrance pupils. A few people stated that a 52mm or smaller filter size was about the limit for lenses that worked with the WWL-1. It was also speculated that the limitation was related to the size of the rear element of the wet optic the flat port in the case of the WWL-1 or the rear element of the WACP series, which seems to imply a geometric limitation in getting the light bundle from the wet optic into the lens front element. See this from Massimimo on his website for example: https://interceptor121.com/2023/03/11/nauticam-wwl-1-on-sony-full-frame-what-to-expect/ All of this is somewhat speculative, but I have yet to see anyone who has posted "I put a 28-xx lens not on the list behind the WWL or WACP and this is what the images looked like" or similar posts. So we just have these bigger lenses are incompatible but no real reason why and no one has tried done behind one of these wet optics and published what they found at least I don't recall seeing any such posts. Some examples might include will the EF 28-70 f3.6-5.6 lens work behind a WWL-1 on full frame or will a 24-70 f2.8L lens work behind a WACP-1, the question has been asked but I don't recall seeing anyone posting what the result is if you try it.

I'm not 72 yet but I feel every kg these days, while it's certainly tempting to want to take your favourite camera UW, there's lighter options that are every bit as good these days. Not saying don't do it but check out the size and weight of a housed D850 and how you would travel with it before leaping in.

Yes there are plenty of examples where FF might have an edge, if the particular scenario is important to you, sure, If you dive it once or twice and don't come back to it FF, APS-C or m43 will all likely produce an acceptable result. I'm not sure how particulates come into your example to favour full frame though. Low light sure particularly with a constant light source, though video lights on a wreck can only illuminate a very small proportion of it I would think.

I don't doubt there are solid reasons for using a FF system and one of them is no doubt, I want one, I can afford it and I'm prepared for the weight and travel issues. However to fair again, shooting at f2.8 is not something everyone can do with the lenses they have and to get the best out of fisheyes behind domes and wide rectilinears requires stopping down to at least f11 for many people's tastes. For me I occasionally run into trouble with sunbursts with Olympus, often due to laziness on my part setting things up but overall I'm happy with what it puts out. I should add this applies to the latest 20MP sensors, the earlier 16MP sensors seem to me to be a step behind.