Choosing a camera format for Underwater Photography

[Interceptor121]

I am sure this will be controversial however do read it all before jumping to conclusions!

Choosing a Camera Format for Underwater Photography

 

[Hoag]

Great info & well said.

 

[Compressor]

Nice information. It's the author's opinion of course.

 

[Interceptor121]

Nice information. It's the author's opinion of course.

Opinion is only related to the suggestion part, the comparisons of SNR, DR and Colors are fact not subject to interpretation

 

[Compressor]

Opinion is only related to the suggestion part, the comparisons of SNR, DR and Colors are fact not subject to interpretation

Yes; I did not mean to say otherwise.

 

[Nemrod]

Computer screens have a DR of what, about 10 stops? Prints, something like 7 stops? The human eye variously awarded around 20 stops? Well, Sony may have a Bionix processor but the human eye has the human brain. Then there is the whole controversy over for example Apple's Retina screens and at what level does the human eye no longer perceive pixilation.

If you are going to take the system approach, that system includes the camera, lenses, sensor and technology, the housing and strobes, yes. But it also includes the viewing media and the human eye/brain. At some point we reach a level beyond which there is no advantage for the camera sensor to be larger, faster, more pixels or whatever is the measure. And for most that happened about 10 years ago.

Some years ago computer chip clock speed was the selling data point for the industry, mine is faster than yours. For digital cameras it has been pixels, I got more pixels than you do and mine are bigger so my camera is better! For truth, there are yet to be improvements in dynamic range and throughput to the final human eye that beholds the image. But I think, somewhere around 20MP for M4:3, maybe 24MP for APS-C and around 40MP for FF could deliver images that are fully realized. But then there is another aspect, data content within the image files, there indeed more could be better for those of us who are masters of manipulation in post processing.

So, I contend, a "best" system would be portable, have the optics that fit the photographers vision. And it must allow easy access to the fundamental aspects of exposure, that being aperture, shutter speed and focus. And saying focus, well, that is now AF speed since nobody knows how to do manual focus anymore.

And there, that is what drove me to a new camera, AF speed! And not opinion, but fact, at least as of last fall, the Sony A6400 was the fastest. I had gotten tired of pushing the shutter button and watching my target disappear into the blue while my camera decided if it was in focus or not. With my Nikonos III I could have taken three or four in focus images. With my cute little S90 rig, no way.

We are reaching a point of diminishing return for investment, as Interceptor says. I could have bought the Sony A7IVR FF and doubled my expenditure and get the "most" or buy the APS-C or M4:3 and get "enough" camera today and future proof by holding in reserve funds to upgrade when we get closer to that 20 stops of DR and someday perhaps a camera system that truly emulates the best UW camera that has ever been, the Nikonos III.

James

 

[Storker]

I don't agree with some of your premises. Particularly this:

An exposure of f/8 on a 16mm lens on Full frame camera is equivalent to an exposure of f/4 on a 8mm lens on MFT.

Yes, in terms of DOF those two are fairly equivalent. But if I'm shooting in murky green water, I'm not stopping down to f/8 if I can shoot at f/4, because I'm prioritizing SNR over DOF. So in other terms than DOF, those two are not equivalent.

 

[Interceptor121]

I don't agree with some of your premises. Particularly this:



Yes, in terms of DOF those two are fairly equivalent. But if I'm shooting in murky green water, I'm not stopping down to f/8 if I can shoot at f/4, because I'm prioritizing SNR over DOF. So in other terms than DOF, those two are not equivalent.

And so? As long as the smaller format has wider aperture this doesn’t matter. Today full frame is f/2.8 fast lens but there are f/2 apsc and 1.4 mft so we are back at the beginning
Only a situation of equivalent DOF and base ISO yields an advantage of one format on another as explained
All the data within the post is 100% accurate for underwater use

 

[Interceptor121]

Computer screens have a DR of what, about 10 stops? Prints, something like 7 stops? The human eye variously awarded around 20 stops? Well, Sony may have a Bionix processor but the human eye has the human brain. Then there is the whole controversy over for example Apple's Retina screens and at what level does the human eye no longer perceive pixilation.

If you are going to take the system approach, that system includes the camera, lenses, sensor and technology, the housing and strobes, yes. But it also includes the viewing media and the human eye/brain. At some point we reach a level beyond which there is no advantage for the camera sensor to be larger, faster, more pixels or whatever is the measure. And for most that happened about 10 years ago.

Some years ago computer chip clock speed was the selling data point for the industry, mine is faster than yours. For digital cameras it has been pixels, I got more pixels than you do and mine are bigger so my camera is better! For truth, there are yet to be improvements in dynamic range and throughput to the final human eye that beholds the image. But I think, somewhere around 20MP for M4:3, maybe 24MP for APS-C and around 40MP for FF could deliver images that are fully realized. But then there is another aspect, data content within the image files, there indeed more could be better for those of us who are masters of manipulation in post processing.

So, I contend, a "best" system would be portable, have the optics that fit the photographers vision. And it must allow easy access to the fundamental aspects of exposure, that being aperture, shutter speed and focus. And saying focus, well, that is now AF speed since nobody knows how to do manual focus anymore.

And there, that is what drove me to a new camera, AF speed! And not opinion, but fact, at least as of last fall, the Sony A6400 was the fastest. I had gotten tired of pushing the shutter button and watching my target disappear into the blue while my camera decided if it was in focus or not. With my Nikonos III I could have taken three or four in focus images. With my cute little S90 rig, no way.

We are reaching a point of diminishing return for investment, as Interceptor says. I could have bought the Sony A7IVR FF and doubled my expenditure and get the "most" or buy the APS-C or M4:3 and get "enough" camera today and future proof by holding in reserve funds to upgrade when we get closer to that 20 stops of DR and someday perhaps a camera system that truly emulates the best UW camera that has ever been, the Nikonos III.

James

My intention was not to start a discussion about the 'best' camera but purely to clarify a few key points that may be useful making choices.
The vast majority of underwater photographers I know were not even photographers before and therefore do not have a full appreciation of some of the concepts let alone the physics behind it.
Everyone is free to choose how to spend their money but my business experience tells me that is very easy to go from being crap to 50% performance, it takes some effort to get to 80% it takes a much more significant effort to get to 95% and after that it may become uneconomical to put more effort for a 1% improvement.
The majority of the improvement is linked to your ability to shoot and not due to equipment I wish people would spend more time learning instead of shopping if that makes sense so hopefully this helps and if it does not well what can you do?
I found very interesting the reading I have done corroborating some empirical observations and when I write this stuff it also helps my thinking

 

[Storker]

As long as the smaller format has wider aperture

Has it? I haven't noticed.

Today full frame is f/2.8 fast lens but there are f/2 apsc and 1.4 mft so we are back at the beginning

"Fast" WA zooms for 24x36 and 15x21 are typically f/2.8. I don't know about Canon, but Nikon has some sweet f/1.8 and f/1.4 primes. My m43 lenses are generally slower. I know Olympus has some nice, fast m43 glass, but they're about as big as the FX and DX glass. And why should I choose an m43 when the camera and glass is about the same size as my FX or DX gear? Size matters, that's why I chose m43 rather than a dSLR for my UW photography.