8 hours ago, Chris Ross said:

yes, but apart from sunbursts, dynamic range I don't think is that useful under water, most shots I take I'm increasing contrast. Don't disagree there are certain situations where it will help. If you look at noise it seems to me the performance is closer than most people think. Here is one example comparing an EM-1 MkII with a Sony A7RV from DXO mark :

You'll see the noise when the EM-1 is set to ISO200 is about the same as when the Sony is set ISO400. Effectively one stop better and shooting wide you may well want to have the Sony at 400 due to stopping down to f11-13, while the Olympus is happy at ISO200 at f8, but either way it's not a huge advantage. of course if you compare true ISO it's about a stop and half difference. The point is m43 can claw back quality by shooting at wider apertures and due to the smaller sensor they are less constrained by dome size.

Here's a link to have a play with if you like:

DXOMARK

Olympus OM-D E-M1 Mark II vs Canon EOS R8 vs Sony A7R V |...

The dynamic range curve is similar. In fact if you throw the Nikon Z8 or the Canon R8 into the pot they all very closely mimic the Sony curve. In fact DXO's most recent test results are from a camera released in 2023, it's like the curves are all so close there is little separate them and other shooting factors come into play like computational photography, AF, high frames/second etc. etc. to differentiate cameras today, making this sort of testing somewhat obsolete.

Now I'm the first to admit these curves don't tell the whole story and certainly you shoot a bit higher ISO without noticeable penalty with full frame and there are other advantages for specific cases, but for general reef shooting and macro where you are shooting within a stop of base ISO it's close to a wash. I've linked in the past a shot taken on an OM-1 at ISO10,000 - it is surprisingly good.

on the topic of large prints it seems to me we are talking A2 and above. If you look at physical prints in the big photo comps, I haven't looked lately but it seems they are mostly in A3 size range or the old 16x20.

It just depends on what you shoot. For macro, I agree that high dynamic range is often not needed. But I’m primarily a shallow water wide angle shooter, and the background in those shots is natural light, where high dynamic range can make all the difference between a shot working or not.

The real noise/image quality differences are greater than shown on the DXO graphs. To make a fair comparison, images need to be normalized to the same resolution. However, DXO downsizes the images to 8mp, which is very inadequate for photographers licensing their photos, making large prints, entering big contests, etc. For people like myself who want to make full use of the 60mp of the Sony A7RV, the useful comparison would be enlarging the Olympus files to 60mp for the comparison (or at least normalize both to a decent resolution in the 30-50mp range).

With my FF setup, I do not have to stop down more or use a higher ISO than MFT. My wide angle can give sharp edges at f/2.8. Though if I am using optics that require stopping down more, my preference is to increase strobe power and exposure length rather than increasing ISO. Either way, I’m rarely shooting at higher ISO than I would be on MFT.

Anyway, there is no one best sensor size. It varies according to the priorities of the individual. For many photographers, MFT provides adequate image quality for how they use their photos, so the size/cost advantages make it their best choice. But for other photographers, maximizing image quality/resolution is the priority, so FF is the best choice.

11 hours ago, Isaac Szabo said:

It just depends on what you shoot. For macro, I agree that high dynamic range is often not needed. But I’m primarily a shallow water wide angle shooter, and the background in those shots is natural light, where high dynamic range can make all the difference between a shot working or not.

The real noise/image quality differences are greater than shown on the DXO graphs. To make a fair comparison, images need to be normalized to the same resolution. However, DXO downsizes the images to 8mp, which is very inadequate for photographers licensing their photos, making large prints, entering big contests, etc. For people like myself who want to make full use of the 60mp of the Sony A7RV, the useful comparison would be enlarging the Olympus files to 60mp for the comparison (or at least normalize both to a decent resolution in the 30-50mp range).

With my FF setup, I do not have to stop down more or use a higher ISO than MFT. My wide angle can give sharp edges at f/2.8. Though if I am using optics that require stopping down more, my preference is to increase strobe power and exposure length rather than increasing ISO. Either way, I’m rarely shooting at higher ISO than I would be on MFT.

Anyway, there is no one best sensor size. It varies according to the priorities of the individual. For many photographers, MFT provides adequate image quality for how they use their photos, so the size/cost advantages make it their best choice. But for other photographers, maximizing image quality/resolution is the priority, so FF is the best choice.

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.

Chris makes an excellent point on “I want one”. Given the costs of underwater photo gear, Buyer’s Remorse is awful thing!

If you feel you are really missing out and would be disappointed by not having FF and, as Chris says, you have the means and appreciate the downsides, then go for it! Dont be faced with Buyer’s Remorse.

Just don’t think it’ll necessarily give you significantly better images. Composition will do that - and that comes at no cost.

Try shooting a wreck in low light with suspended particulate using off camera constant light sources and you'll see why a bigger sensor is a benefit.

1 hour ago, Grantmac said:

Try shooting a wreck in low light with suspended particulate using off camera constant light sources and you'll see why a bigger sensor is a benefit.

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.

5 hours ago, Chris Ross said:

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.

For my archaeological work, lack of light due to both depth and being in the shadow at the foot of a fringing reef wall will be an issue for some of the images I hope to capture that show the wider wreck site. Obviously a pair of Retra Maxi's will light up foreground things, but it will be nice if I can capture things in the background as well.

I stayed with APS-C for practical and financial reasons. I had a Sony A6000 with a Seafrogs housing that was a kind of universal, and when I upgraded to A6400 it was still fitting to the old housing. This setup I mainly used for videos. Later I upgraded the housing to a more ergonomic Nauticam housing (used one). I'm quite happy with the video quality and the ergonomics of the housing. I considered only once to switch to full frame. I had a project to film in a lake during night. Switching to FF Sony and finding a proper wide angle rectilinear lens with the fitting dome port in a Nauticam housing would have been a serious investment (probably over 10K Euro). Finally I just bought a 11 mm 1.8 lens to replace the F4 10-18mm lens for this project. As I remember it was below 500 Euro. I'm quite happy with the results. Would a FF camera produce better material? Probably. But not by a great margin and certainly not 20X better. Fast lenses are relatively cheap for APS-C cameras and they can solve issues with low light filming.

9 hours ago, Davide DB said:

Practically nobody takes photos in ambient light where the camera has to try to adapt to ambient conditions. Here everyone uses strobes!

I would say i disagree with two of the sentiments:

1) Most of my images expose the background, so that is a normal use case not a unique one- even if a close up and definitly CFWA. I find ISO (aka light) to be the major compositional hurdle in much of my image making. Sure packages are great at removing noise - but they all still do it at the reduction of sharpness. Absolutely agree that in this sense a smaller sensor allows an easier to shoot fStop that allow more relative light to the sensor -but I will sacrafice corners and either crop or just live with it when I need to drop below f/13. Also a couple of stops provided by wet optics also brings things closer - but $$ and size.

2) I have never wanted less than "more" dynamic range. I can never have enough especially when trying to get the darks to come alive to balance bright foreground subjects.

I think there are very strong arguments for M43/aps-c/ and FF. All can capture amazing images - no doubt. But I think we are a group that constantly pushes the abilities of even modern sensors to their limit - even though we often (if not pretty much always) are adding light with strobes/lights.

Edited August 22Aug 22 by ColdDarkDiver
typo

19 hours ago, Chris Ross said:

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.

Particulate greatly reduces how much light you can throw at the subject and the distance you can throw it from before all you are illuminating is the water.

7 hours ago, Grantmac said:

Particulate greatly reduces how much light you can throw at the subject and the distance you can throw it from before all you are illuminating is the water.

That’s been my experience, too. One ends up with images that have low contrast. Lightroom’s Dehaze is a real life-saver, but it’s only a work-around. The camera might have lots of dynamic range, but you don’t get the benefit when shooting in haze … and we often have these conditions here in North Carolina.

21 hours ago, ColdDarkDiver said:

1) Most of my images expose the background, so that is a normal use case not a unique one- even if a close up and definitly CFWA. I find ISO (aka light) to be the major compositional hurdle in much of my image making. Sure packages are great at removing noise - but they all still do it at the reduction of sharpness.

There clearly are ways to reduce noise and INCREASE sharpness at the same time during post-processing.

Yes, this is AI - at its best. And these algorithms are likely driving much of the improved signal/noise ratio in the new camera bodies' jpg engines (no matter which sensor format).

12 hours ago, Proteus said:

That’s been my experience, too. One ends up with images that have low contrast. Lightroom’s Dehaze is a real life-saver, but it’s only a work-around. The camera might have lots of dynamic range, but you don’t get the benefit when shooting in haze … and we often have these conditions here in North Carolina.

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.

On 8/21/2026 at 3:22 AM, CCRphoto said:

. . . given that we are documenting a wreck that is basically unique as no other intact wreck from this era of sea travel and maritime trade has ever been found, we owe it to history to get the best images possible.

OK now, around here you can’t just drop a statement like that, the peanut gallery demands more info! At least give us some hints - please!

56 minutes ago, Troporobo said:

OK now, around here you can’t just drop a statement like that, the peanut gallery demands more info! At least give us some hints - please!

LOL!

I will try to keep the history lesson short😄

Initial maritime trade from Egypt to India took place initially over a period of several hundred years and started around 250 BC but possibly earlier. In 30 BC the Romans conquered Egypt and then that opened up trading routes from Rome all the way to the west coast of India - and possibly further. Essentially the Romans sailed goods across the Mediterranean to the Nile, then omn smaller boats they were transported down the Nile, and then carried overland to various ports on the Red Sea coast where they were then loaded onto a fleet of vessels that all sailed at once each year to catch the monsoon winds to India. They then did their trade and bartering etc while waiting two months for the winds to change to enable them to return to Egypt, and the goods that they obtained from India were then sent up the Nile and across the Mediterranean to Rome.

Altogether there are four known shipwreck sites from this period although given the vast number of ships sailing the route during the Roman period there are no doubt more to be discovered. Two of the sites consist solely of scattered amphoras, one site has some timbers from the bottom of the hull and some scattered artifacts, and then there is the site that I discovered in 1991. From the style of its cargo of amphoras we have been able to date the wreck as somewhere between AD 10 & AD 30 - so basically 2000 years ago.

Because the Red Sea waters are low in oxygen below about 35 metres, the hull of this vessel is intact - the timbers are still solid etc. We haven't done any testing of the timber yet as currently the archaeology permit does not allow us to raise any objects, but we believe that the timber is mahogany, which along with cedar has been used in shipbuilding in Egypt since at least 1500 BC, the mahogany and cedar came from Lebanon.

So this wreck is the only known intact wreck from the period of maritime trade between Egypt and India - and so historically it is quite important as we don't know a lot about the maritime aspects of that trade. We do know that the demand from the elites in Rome for exotic spices and silks etc from India was so great that it nearly sent the Roman Empire broke! Given that this ship was loaded with amphoras which probably contained olive oil and wines, this ship was loaded with an outbound cargo destined for India.

Just up the coast a little is where the Egyptians launched the Expeditions to the Land of Punt some 3500+ years ago - if we were to ever find a wreck from that trade then it would epic!

4 hours ago, Chris Ross said:

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.

I'll play :) (in good fun - I appreciate what was in this post - but will provide my experience).

So - yes and maybe? My take on this is that you want to use just enough light to light the subject but without blowing out the water but getting the depth of color that it has. ISO is critical. By doing this - and maximizing the dynamic range captured by the camera so you can bring it all together in post (if you need to) but you still need the light to bring out the colors that will otherwise be lost. Under and over exposed means you can bring it back if you need be with the latitude of modern sensors, but using everything the shot has is ideal.

I find that the most important thing in murky water (which I know and love) is that one has to adjust their strobes for each shot to only light the subject and no more. In clear water, set and forget and it is fine, but in murky it is a constant movement of strobes in, out, angled out, angled in - for each shot to overlap just what one wants lit and as little water as possible. It is set by distance to the subject more than anything else... which also means adjusting power output.

I also think that white point and black point setting is really important, but touching on the importance of all the dynamic range that is good, I thought I would add a few examples. These are all straight from camera - R5 (which is pretty solid dynamic range). I'm including the histogram (untouched) to show the need to expose the background and it is not only black and white point setting.

Canon R5: Straight from Camera:

I used all the dynamic range and it is the darks that make this something intriguing - and this is ISO 1600 - f13.

Or - Kelp experience (I'm cheating here since this was ISO 100 since I was shooting sun but i think it shows how we are still using all of the dynamic range available)

(Ok this one I cropped but I didn't impact the histogram with it but as shot - it exposed the background and lit the foreground while capturing all the light and information possible).

@ColdDarkDiver Could you perhaps reload those images as .jpgs?

4 hours ago, ColdDarkDiver said:

I'll play :) (in good fun - I appreciate what was in this post - but will provide my experience).

So - yes and maybe? My take on this is that you want to use just enough light to light the subject but without blowing out the water but getting the depth of color that it has. ISO is critical. By doing this - and maximizing the dynamic range captured by the camera so you can bring it all together in post (if you need to) but you still need the light to bring out the colors that will otherwise be lost. Under and over exposed means you can bring it back if you need be with the latitude of modern sensors, but using everything the shot has is ideal.

I find that the most important thing in murky water (which I know and love) is that one has to adjust their strobes for each shot to only light the subject and no more. In clear water, set and forget and it is fine, but in murky it is a constant movement of strobes in, out, angled out, angled in - for each shot to overlap just what one wants lit and as little water as possible. It is set by distance to the subject more than anything else... which also means adjusting power output.

I also think that white point and black point setting is really important, but touching on the importance of all the dynamic range that is good, I thought I would add a few examples. These are all straight from camera - R5 (which is pretty solid dynamic range). I'm including the histogram (untouched) to show the need to expose the background and it is not only black and white point setting.

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.

Noise & dynamic range:

Maybe one should stop discussing sensor sizes and instead refer to pixel sizes? After all, you can buy full-frame cameras from 24 Mpx all the way up to 61 Mpx. The larger a pixel is, the more light it can collect and as far as I understand this translates to higher dynamic range and better signal/noise ratios.

Considering that the full-frame sensor has a 3.8-fold larger surface than a M43 sensor, the pixel size of a 20 Mpx M43 sensor should correspond to a hypothetical 77 Mpx full-frame sensor. If those two sensors were built exactly alike, then their signal/noise and dynamic range should be the same (per pixel). I know there are other things to consider, but let's keep it simple.

In that comparison, the 61 Mpx FF camera is thus not soooo different from a 20 Mpx MFT. Sure, you can add up neighboring pixels from the 61 Mpx shot and thereby down-sample to 20 Mpx. This will improve singal/noise, but then you lose the argument that the 61 Mpx allows for much more cropping.

(Interesting to follow where this thread has gone from the original post. Special thanks for the history and archeology info, VERY much looking forward to more posts on this and especially to the eventual opening of the museum! Also the practical info is wise - you can pay a lot of extra luggage for the price of a new kit, I agree.)

On 8/20/2026 at 5:22 AM, CCRphoto said:

I will remind myself how lucky I am next time I am doing yet another two hours of deco above the wreck🤣

What limits me most with my project diving is bottom time vs decompression obligation, and weather - if I could go back in time 2000 years I would tell them "no don't sink it over there - sink it up there - behind the reef - so that there is a bit of protection when I come back in two thousand years to document your ship(wreck)"

Having said that, given that we are documenting a wreck that is basically unique as no other intact wreck from this era of sea travel and maritime trade has ever been found, we owe it to history to get the best images possible.

That’s a wonderful niche project. If your budget prioritizes image quality, how about the the Fuji GF series? https://www.nauticam.com/products/na-gfx100ii-housing-for-fujifilm-gfx100ii-camera

1 hour ago, humu9679 said:

That’s a wonderful niche project. If your budget prioritizes image quality, how about the the Fuji GF series? https://www.nauticam.com/products/na-gfx100ii-housing-for-fujifilm-gfx100ii-camera

or something like a Red camera:

RED Digital Cinema

RED Digital Cinema | Professional Cameras

RED is the leading manufacturer of professional digital cinema cameras. Explore RED's modular camera system and groundbreaking image quality.

7 hours ago, humu9679 said:

That’s a wonderful niche project. If your budget prioritizes image quality, how about the the Fuji GF series? https://www.nauticam.com/products/na-gfx100ii-housing-for-fujifilm-gfx100ii-camera

102MP must be nice for some people, but the extra storage capacity and processing power... nah.

6 hours ago, SwiftFF5 said:

or something like a Red camera:

RED Digital Cinema

RED Digital Cinema | Professional Cameras

RED is the leading manufacturer of professional digital cinema cameras. Explore RED's modular camera system and groundbreaking image quality.

I think 24.5MP (Nikon) or 33MP (Sony) will be enough.

wow

I though the original question was quite simple but this has turned into a technical pandora's box and I have been fascinated to read the replies

I'm on a sony alpha 6xxx set up which is firstly portable and secondly cheap(ish) I have always presumed that if you are shooting with a dome, the dome becomes a part of the lens system and may well be the most important quality limiting step as most lenses, even cheap ones, are pretty good.

The second thing, at my stage is that there are far more significant factors limiting image quality than sensor size (technique, experience and so on) but I posted the original question while I was wondering if going from alpha 6xxx to alpha 7 ff would make much difference. My guess is not...

thanks for all the excellent replies

34 minutes ago, Mike Saunders said:

wow

I though the original question was quite simple but this has turned into a technical pandora's box and I have been fascinated to read the replies

I'm on a sony alpha 6xxx set up which is firstly portable and secondly cheap(ish) I have always presumed that if you are shooting with a dome, the dome becomes a part of the lens system and may well be the most important quality limiting step as most lenses, even cheap ones, are pretty good.

The second thing, at my stage is that there are far more significant factors limiting image quality than sensor size (technique, experience and so on) but I posted the original question while I was wondering if going from alpha 6xxx to alpha 7 ff would make much difference. My guess is not...

thanks for all the excellent replies

My conclusion was that you should spend lots of money for some marginal improvement in some area of photography/videography.

as a footnote, years ago I used to dive with a Nikon 35mm film body with a 60mm macro lens

I now keep the lens at work in the drawer in clinic with an old d700 body to take pictures of patients - it still takes beautiful pictures

every time I get it out I am staggered how heavy it is and equally staggered that I used to take it underwater in an Ikelite housing

7 hours ago, Mike Saunders said:

wow

I though the original question was quite simple but this has turned into a technical pandora's box and I have been fascinated to read the replies

I'm on a sony alpha 6xxx set up which is firstly portable and secondly cheap(ish) I have always presumed that if you are shooting with a dome, the dome becomes a part of the lens system and may well be the most important quality limiting step as most lenses, even cheap ones, are pretty good.

The second thing, at my stage is that there are far more significant factors limiting image quality than sensor size (technique, experience and so on) but I posted the original question while I was wondering if going from alpha 6xxx to alpha 7 ff would make much difference. My guess is not...

thanks for all the excellent replies

As UW photographers, we shoot a whole system. And we shoot in water. Singeling out one part like the sensor, a lens, the camera model, port/dome, etc will not always be productive.

I think this episode of the UWP show gives some perspective and food for thought. Many images shot with equipment way inferior to what we have today.

My fav of the lot is shot on a 12 mp aps-c sensor, noisy as hell.

It’s fun to measurbate, but it won’t produce anything. YMMV.

Edited August 26Aug 26 by Christian K