technically speaking what are the advantages and disadvantages of the APSC and full frame cameras?

clearly bigger sensor and more pixels with full frame, but beyond that are there any specific technical or optical matters of relevance to UW photography?

Mike S

I've used both, Mike.

Like so many things with underwater photography, what you can achieve in that environment and what the two cameras might be capable of, are two different things.

I used a D800 (FF) for about 4 years and a D500 (APS-C) for 9 years. Other than having more pixels to crop, I honestly could not see the difference for the types of images I use: selling to stock agencies, on my computer, sending to friends, the occasional A2 print....

For me, and I'm sure others will argue, the disadvantage of FF is the size of the gear, the extra difficulty of housing a rectilinear with a huge port - and the cost of the lenses. I know wet lenses can make a difference for wide-angle and might be easier to "house".

For that it's worth, I would not go back to FF. I'm actually moving down again to M43!

what you can achieve in that environment and what the two cameras might be capable of, are two different things

very much so!

I think we're spoiled nowadays.

I have a Sony A1 as I wanted it for topside work, where it shines. I then built a UW system around it which I love.

However, if I was starting from scratch I would probably go M43 now for the size and cost advantages. unless you want to crop big or print huge then I struggle to see any advantage with modern AF capabilities, especially if you're half decent with PP

I’ve gone from small sensor to FF and back again. Sadly, it reflects more on my wallet than in the images I create.

Like many I started with smaller sensors years ago. When FF came out I got excited and switched. When I look back across my library I see images that I like from both kinds of sensors (and on the FF side I’m comparing excellent machines like the Nikon D850 and Sony A7RV). When I got great pictures the subject, or the environment dominated the results.

Recently I switched to the smaller sensor Canon R7. The determining factor was travel. Full frame can add to a lot of size and weight. M43 and similar smaller sensors years give more than enough performance and are far easier to travel with.

One disadvantage of smaller cameras, at least with Nauticam, is that the port size doesn't allow many common lenses to load from the rear.

That said if I can get into a M4/3 housing which uses N120 or similar ports I might be very tempted. Although something like an A7CR isn't much bigger.

1 hour ago, Grantmac said:

One disadvantage of smaller cameras, at least with Nauticam, is that the port size doesn't allow many common lenses to load from the rear.

That said if I can get into a M4/3 housing which uses N120 or similar ports I might be very tempted. Although something like an A7CR isn't much bigger.

N100 ports would be big enough to solve that problem and Isotta have solved it as they use 102mm ports for m43. Seriously though the N85 is a little limiting - it would be nice to load the Canon 8-15 from the back but not worth changing systems over completely. It seems to me that Nauticam could consolidate their port offerings by scratching the n85 ports and just offer N100 and N120, for one thing they could have every port in native size and not need adapters. For example the 140mm port and 4.33" comes in N120 and N85 but not N100.

On the question APS-C and FF I would say that m43 is very close in performance to APS-C and for most people it's enough. The lenses offered in m43 are comprehensive between what OM and Panasonic offer, 3 macro focal lengths, native fisheyes a wide range of rectilinears, 4 or 5 lenses that work with WWL optics plus they readily take adapted lenses via Metabones.

The ability to use the Canon 8-15 means you have a fisheye and at least in field coverage a rectilinear 14-28 equivalent in one lens, looking another way it's a Fisheye plus about 2/3 of the focal range of a WWL. The 8-15 gets to 28mm equivalent in reach while a WWL gets to 30-35mm depending on the lens used with it. You can't do this with FF Canon or Nikon, with Sony you can combine a Sony 2x with the 8-15 but it takes a slight quality hit which many find acceptable. Canon you can do it but involves taking a file to an after market RF-EF adapter. Other than that you are looking at very heavy and pricey fisheye conversion port.

To me the first question became mirror or mirorless, followed by then choosing FF, APS-C or M43.

I was initially leaning towards an OM-1 MkII and thus M43, however I'm heading to the GoDiving show in Sydney in a couple of weeks to take a good look at the Nauticam Z5ii housing with a view to going FF. The main reason for this is after reading some posts on here about noise and how pixel size and density have a fair bit to do with noise and then doing some research - it seems to me that the best pixel to sensor size ratio is a fullframe 24.5 megapixel sensor. I could be miles wrong though.

3 hours ago, Mike Saunders said:

what you can achieve in that environment and what the two cameras might be capable of, are two different things

very much so!

9 hours ago, Chris Ross said:

4 or 5 lenses that work with WWL optics

IIRC all 14-42mm zooms except the Oly pz pancake were discontinued. At one point Pana decided that kit lens were 12-32mm or 12-60mm zoom and WWL was designed on FF 28mm.

Yes it's plenty of used lens out there but It is a shame not to be able to use a modern lens.

With 12mm the situation gets complicated and the price goes through the roof.

Edit:

For the 12mm zooms we have two options:

• 12-32mm + WWL-C. I guess similar results as 14-42 + WWL-1. This lens is discontinued as well.

• 12-35mm + WACP-1 Really pricey. Virtually no compromises but I've never seen one out there.

The 12-60mm has a lens excursion too long for a useful port configuration.

Edited August 20Aug 20 by Davide DB

17 hours ago, TimG said:

what you can achieve in that environment and what the two cameras might be capable of, are two different things.

This could be my new signature 😁

2 hours ago, CCRphoto said:

To me the first question became mirror or mirorless, followed by then choosing FF, APS-C or M43.

I was initially leaning towards an OM-1 MkII and thus M43, however I'm heading to the GoDiving show in Sydney in a couple of weeks to take a good look at the Nauticam Z5ii housing with a view to going FF. The main reason for this is after reading some posts on here about noise and how pixel size and density have a fair bit to do with noise and then doing some research - it seems to me that the best pixel to sensor size ratio is a fullframe 24.5 megapixel sensor. I could be miles wrong though.

It goes back to the discussion on the use of your images. If it for pleasure viewing, sharing with friends, artistic creation, some sales, then I would argue that for the vast majority of u/w photographers, FF is unnecessarily expensive and creates problems for travelling in terms of weight and volume of gear.

But if you feel that not having FF is somehow missing out and just disappointing, then fair enough. But in terms of real, viewable quality, naah. You'd have to be a serious pixel peeper or have very demanding clients to worry about noise, pixel size and density. On a modern camera with modern lenses the water turbidity creates more problems than those three ever will! The series camera bodies and lenses produced now are capable of producing amazing imagery irrespective almost of the sensor size. I came to the conclusion that underwater the FF thing is a marketing trick which harnesses the old 35mm standard. Topside, why not have FF? (Unless you decide the much smaller M43 is handier/travel friendly - and I can sure see the argument for that)

3 hours ago, CCRphoto said:

To me the first question became mirror or mirorless, followed by then choosing FF, APS-C or M43.

I was initially leaning towards an OM-1 MkII and thus M43, however I'm heading to the GoDiving show in Sydney in a couple of weeks to take a good look at the Nauticam Z5ii housing with a view to going FF. The main reason for this is after reading some posts on here about noise and how pixel size and density have a fair bit to do with noise and then doing some research - it seems to me that the best pixel to sensor size ratio is a fullframe 24.5 megapixel sensor. I could be miles wrong though.

You have to remember that while some of these testing and review websites might be useful, and well tell you various things about noise measurements and which combination has the best noise characteristics. They are however run by people who measure photographs rather than make photographs in many cases. the differences are often only visible when viewing the image at 100% on Photoshop and even then you need to look at them sideways multiple times to pick the differences.

If you look at the images as a whole image it can be hard to pick the difference between well exposed images taken on m43 and full frame unless you are talking about extremely large images or very high ISO, but even then m43 can produce some amazing images in low light. You have to go down to a compact like a TG-7 with a tiny sensor and not expose it that well to produce an image that is obviously not as nice. Back in the day when digital first started there were big differences, these days things are much closer and gains are very much incremental.

It's not that FF doesn't have it lace but for me and many others the gains aren't enough to offset the downsides of ownership.

42 minutes ago, TimG said:

It goes back to the discussion on the use of your images. If it for pleasure viewing, sharing with friends, artistic creation, some sales, then I would argue that for the vast majority of u/w photographers, FF is unnecessarily expensive and creates problems for travelling in terms of weight and volume of gear.

But if you feel that not having FF is somehow missing out and just disappointing, then fair enough. But in terms of real, viewable quality, naah. You'd have to be a serious pixel peeper or have very demanding clients to worry about noise, pixel size and density. On a modern camera with modern lenses the water turbidity creates more problems than those three ever will! The series camera bodies and lenses produced now are capable of producing amazing imagery irrespective almost of the sensor size. I came to the conclusion that underwater the FF thing is a marketing trick which harnesses the old 35mm standard. Topside, why not have FF? (Unless you decide the much smaller M43 is handier/travel friendly - and I can sure see the argument for that)

In my case I think that it comes down to where I think that my archaeology project might be heading (possibly an entire museum built basically around it), and wanting to record things insitu with very good resolution both for scientific purposes and as some of the images will certainly end up being used in the museum.

2 minutes ago, Chris Ross said:

You have to remember that while some of these testing and review websites might be useful, and well tell you various things about noise measurements and which combination has the best noise characteristics. They are however run by people who measure photographs rather than make photographs in many cases. the differences are often only visible when viewing the image at 100% on Photoshop and even then you need to look at them sideways multiple times to pick the differences.

If you look at the images as a whole image it can be hard to pick the difference between well exposed images taken on m43 and full frame unless you are talking about extremely large images or very high ISO, but even then m43 can produce some amazing images in low light. You have to go down to a compact like a TG-7 with a tiny sensor and not expose it that well to produce an image that is obviously not as nice. Back in the day when digital first started there were big differences, these days things are much closer and gains are very much incremental.

It's not that FF doesn't have it lace but for me and many others the gains aren't enough to offset the downsides of ownership.

If the images end up on a wall in a museum then I would imagine that they would be quite large. We would be a bit further along with the project by now if everyone hadn't started lobbing bombs again in the Muddle East☹️

Scientific work and museum exhibits are great projects, but not many of us have the luck to participate in that kind of event. Great stuff!

As for the original question - may I ask what limits your photo archive most, image quality or diving opportunity? An honest answer may tell you where the money should go.

And, since we shouldn’t bite the hands of the equipment dealers that feed this site:

May I throw in that perhaps a better strobe or snoot might benefit your pictures more than a bigger sensor? I confess to GAS: I also feel better when traveling with something new to something blue …

Edited August 20Aug 20 by Klaus
Clarify meaning

If we start with the premise that a M43 sensor is good enough for most (and understanding that’s not true for all) I’d like to offer an example.

It’s true that the size of the housing is similar or identical if comparing FF and M43. The difference is in the lenses, and the ports. Lenses get both smaller and lighter, especially if you plan for a max aperture of 4.0 or higher. As the lens becomes smaller so does the port. Like some have said I would avoid M85 systems, but M100 is very useful. If you design for the lenses I’ve named above M100 ports can become your go to.

A smaller aperture might raise concerns about ISO noise. In my mind sensor noise is not what it once was. Not only is it quite low for both FF and M43, but Lightroom and other products can pretty much make it go away.

So for me a travel-optimized system is M43 (or similar), f4.0 and such lenses, and M100 ports. That said, if you need wall sized and such, as some have written, the requirements are completely different. I’m just writing for those who’s photos might end up on a screen, or a medium sized print.

Gary

3 hours ago, Klaus said:

Scientific work and museum exhibits are great projects, but not many of us have the luck to participate in that kind of event. Great stuff!

As for the original question - may I ask what limits your photo archive most, image quality or diving opportunity? An honest answer may tell you where the money should go.

And, since we shouldn’t bite the hands of the equipment dealers that feed this site:

May I throw in that perhaps a better strobe or snoot might benefit your pictures more than a bigger sensor? I confess to GAS: I also feel better when traveling with something new to something blue …

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.

If image quality is a priority and you plan on making large prints, high resolution (40-60mp) full frame is the best tool for the job. I absolutely benefit from the lower noise, better dynamic range, and higher resolution of full frame sensors compared to smaller ones. But I’m a pixel peeper who prioritizes image quality and sells photos that get printed large. On the other hand, others commenting here are completely right that sensor size doesn’t matter nearly as much if you’re only sharing images on the web/social media.

Edited August 20Aug 20 by Isaac Szabo

Wide rectilinear shots is probably where FF has the most advantage.

Edited August 20Aug 20 by Grantmac

16 hours ago, Isaac Szabo said:

If image quality is a priority and you plan on making large prints, high resolution (40-60mp) full frame is the best tool for the job. I absolutely benefit from the lower noise, better dynamic range, and higher resolution of full frame sensors compared to smaller ones. But I’m a pixel peeper who prioritizes image quality and sells photos that get printed large. On the other hand, others commenting here are completely right that sensor size doesn’t matter nearly as much if you’re only sharing images on the web/social media.

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.

But then I do not understand one thing...

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

So let us imagine having an Olympus M43 and a Sony A7RVI photographing the same scene.

If the flashes are adjusted so that each of the two cameras records a properly exposed scene, I do not understand where this noise comes from.

If the scene is too dark, you increase the flash power.

In other words, taking it to the extreme, for what we are talking about, underwater photos are like a photo shoot in a studio. Where the light is adjusted by strobes and lights and not by the camera sensor. In a studio, the photographer doesn't work at ISO 1600. He increases the light power.

It is different if I took photos in ambient light at dusk or in low light conditions. I would be forced to raise ISO to levels where I would probably notice the differences.

P.S.

I could be very critical about the low light conditions that everyone claims to be in... 😉

55 minutes ago, Davide DB said:

But then I do not understand one thing...

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

So let us imagine having an Olympus M43 and a Sony A7RVI photographing the same scene.

If the flashes are adjusted so that each of the two cameras records a properly exposed scene, I do not understand where this noise comes from.

If the scene is too dark, you increase the flash power.

In other words, taking it to the extreme, for what we are talking about, underwater photos are like a photo shoot in a studio. Where the light is adjusted by strobes and lights and not by the camera sensor. In a studio, the photographer doesn't work at ISO 1600. He increases the light power.

It is different if I took photos in ambient light at dusk or in low light conditions. I would be forced to raise ISO to levels where I would probably notice the differences.

P.S.

I could be very critical about the low light conditions that everyone claims to be in... 😉

What you describe is exactly the situation for many macro photos...

In many WA photos, however, shutter speed, aperture and ISO are adjusted to give enough ambient light for the background, otherwise the photo may look as beeing from a nightdive (when everything is mostly lit by the flash(es)). Flashe(es) are normally only able to light the foreground object(s)...

When a little deeper, even in very clear waters and sunshine (not to speak about our lakes)), the camera settings come soon to their borders to give a pleasant background (motion blurr, corner sharpness, noise and sometimes even dynamic range)...

Edited August 21Aug 21 by Architeuthis

20 minutes ago, Architeuthis said:

This is exactly the situation for many macro photos. In many WA photos, however, shutter speed, aperture and ISO are adjusted to give enough ambient light for the backbround, otherwise the photo may look as beeing from a nightdive (when everything is mostly lit by the flash(es)). Flashe(es) just to light the foreground object(s)...

When a little deeper, even in very clear waters and sunshine, the camera settings come soon to their borders to give a pleasant background (motion blurr, corner sharpness, noise and sometimes even dynamic range)...

Yes, I simplified a lot. You brighten the background by changing the ISO, basically exposing for the ambient light. But here Chris post comes into play: to get decent corners in full frame you have to work with approximately two stops narrower aperture, and so from the chart he posted you can see that the SNR is practically identical. In short, technically I do not see all this difference.

Then for large prints I agree.

But I still think that this endless debate comes down to corner cases.

Camera manufacturers develop and market the full frame format to meet purely terrestrial needs, such as the search for a shallow depth of field for portraits or clean images at very high ISO for reportage. None of these features is optimized for shooting through a glass lens submerged in a liquid.

Underwater optical physics, if isolated from the global market, would benefit more from the balance offered by smaller sensors. Micro four thirds allows the use of hydrodynamic domes and guarantees a native depth of field that greatly helps composition while diving.