Choosing a camera format for Underwater Photography

[Interceptor121]

You seem rather fixated on DOF. What if DOF isn't the end-all, be-all, but if decent SNR is more important than optimal DOF?

Many of us shoot under less than optimal conditions. Often, we have to decide on our priorities. Which are given by the situation at hand, not by some keyboard warrior musings. And we have to choose what to let go. Which may be different from what you choose. What you choose may well be perfect for you, but don't bet your savings that it's perfect for everybody else. Which you seem to do.

I, like you, have chosen to shoot m43 under water. Because given all the pros and cons, it's the best solution for me. I know people who choose to shoot 24x36. Instead of quarreling with them, strongly believing that my solution is the best for them, I choose to accept that they have other priorities and that they - who more than often present as at least as competent as I am - have weighed the pros and cons differently.

Am sorry but you are not understanding the post at all. DOF is irrelevant to the discussion when in optics you talk about DOF constrained you make sure the same amount of light goes through the lens irrespective of crop factor

Example a 24mm lens on FF at f/4 has a gap of 6mm to let the light go through, a 12mm on MFT at f/2 will have the same 6mm physical aperture if you don't balance this the comparison is incorrect. Once you have done that you need to calculate the illuminance on the surface as MFT is 1/4 of full frame this means the intensity is 4 times
So this says that if your MFT was at f/2 and ISO 100 your FF camera will be at f/4 ISO 400 obviously exposure time is constant
Once you take into account the two stops distance SNR and DR are equal differences in performance are not due to size but to other construction and design features.
A larger sensor is only superior when you shoot at the minimum lowest ISO and this is because it will collect many more photons than a cropped one APSC or MFT it does not matter and I do not care what is best those are just facts. Likewise when it goes to real low light performance pixel size is what matters at equal number of pixels this is the reason why a professional camera like a Nikon D6 can push a higher ISO than a D500 the pixels are much larger and still retain a good DR. If this is what works for you then great if not then is not required. However it also shows that actually at some point this benefits saturates and more pixels are better than less if you look at D850 vs D5 for example.
I am just replying to the messages because they keep banging on incorrect fact and not take into account what I have written. You say ah ok but I don't need to be at f/8 I can go to f/4 and I say ah ok I can go to f/2 at the end each system has equivalent fast lenses so this becomes soon pointless and out of the scope of a discussion on underwater photography.
Large majority of shots happen in a given set of aperture shutter and ISO for each format probably 70-80% and then there are exceptions. It may well be that for a specific use case a specific format is better however it is important to make the right choices otherwise even those benefits are eliminated and this was the whole point of writing the post
It seems more the case at times that someone buys camera A because they believe in some fairy tales and then when they find out is not true they start coming out with a series of exceptional circumstances to justify their choices while actually you can't

 

[Rollin]

I find your writings interesting, don't be mistaken. But people can read them as solely a plea for m43.

And while you could assume that pictures of Orca are close beneath the surface, they only visit the fjords in winter. And winter far above the Actic circle is, well, very dark.

I'm not going to buy equipment worth thousands of dollars just for trips like this, my speciality lays elsewhere. But a GH-5 just did't cut it, and noise reduction is just horrible, whatever the format. But this is only my humble opinion.

 

[Interceptor121]

I find your writings interesting, don't be mistaken. But people can read them as solely a plea for m43.

And while you could assume that pictures of Orca are close beneath the surface, they only visit the fjords in winter. And winter far above the Actic circle is, well, very dark.

I'm not going to buy equipment worth thousands of dollars just for trips like this, my speciality lays elsewhere. But a GH-5 just did't cut it, and noise reduction is just horrible, whatever the format. But this is only my humble opinion.

That's life. There is no MFT plea I use this in the examples as the crop is 2x and it is easier to calculate

On land it is clear that full frame is unbeatable underwater due to dome port optics the benefits are pretty much equalised so cropped formats APSC or MFT perform almost identical if you don't inject mountains of cash into the exercise.
I have shot FF APSC and MFT on land underwater FF has never been attractive due to the bulk. Right now with the MFT bodies that I have GH5 and G9 the size is identical to APSC however the optics are much smaller.
Until MFT was 16 Megapixel I had also a Nikon DX now with 20 Megapixel it makes no sense and I got rid of a compact camera because of newer phones. I could have decided to hang on to a DX but then we were always carrying a compact around because of the weight. I think the Nikon D7200 has been an amazing camera and it is a shame Nikon have decided to cap themselves to 20 MP DX camera just to avoid conflict with the FX siblings

Right now the predominant number of competitions wide angle and macro are won by APSC camera but that is because of the historical ease of getting ports and lenses more than sensor quality

 

[VsubT]

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

Between this and these 2 quotes from the blog post:

I recently posted on WetPixel a discussion that aimed at being provocative about the gap between APSC and MFT cameras.​

The comprehension of some of the concept may be too hard for many so I will attempt a simplification.​

the tone reads like this is a compact / M43 fanboy post in the guise of a technical analysis. I agree that both smaller formats can produce great results, but they have limitations too. Focusing the comparison on wide angle is a pretty specific case, and one that not a lot of people are even good at shooting.

A question: is this all based on references and theory, or have you tested full frame DSLR and mirrorless setups in the conditions described yourself (not ”the other guy on the boat had a DSLR”)? If so, which ones?

Lance

 

[Interceptor121]

It is a sensor analysis not a camera field test and what you ask nobody actually does anyway
I have been multiple times on boats where we would share the best shots and it is quite clear that there was no difference due to sensor in the shots taken
Whats is exactly your concern anyway and what are the limitations you mention?
Wide angle is where sensor is most important as it has all challenges DR noise and color macro is less so and an easier case with even leas differences

 

[VsubT]

It is a sensor analysis not a camera field test and what you ask nobody actually does anyway
I have been multiple times on boats where we would share the best shots and it is quite clear that there was no difference due to sensor in the shots taken
Whats is exactly your concern anyway and what are the limitations you mention?
Wide angle is where sensor is most important as it has all challenges DR noise and color macro is less so and an easier case with even leas differences

So that’s a no. Think I’ll look elsewhere for advice. Thanks,

Lance

 

[Interceptor121]

It is a sensor analysis not a camera field test and what you ask nobody actually does anyway
I have been multiple times on boats where we would share the best shots and it is quite clear that there was no difference due to sensor in the shots taken
Whats is exactly your concern anyway and what are the limitations you mention?

So that’s a no. Think I’ll look elsewhere for advice. Thanks,

Lance

I was not planning to give you any

 

[tarponchik]

By the way fish schools at 40 ft are not an issue and I shoot them with strobes
View attachment 572658Snapper Photography by Interceptor121, on Flickr
This is at 20 meters which is 65 feet I think

Sure. Point-blank shooting with a fish-eye?

 

[Interceptor121]

I think I have hit a few sore bums here but hey that's life

 

[Storker]

Between this and these 2 quotes from the blog post:

I recently posted on WetPixel a discussion that aimed at being provocative about the gap between APSC and MFT cameras.​

The comprehension of some of the concept may be too hard for many so I will attempt a simplification.​

the tone reads like this is a compact / M43 fanboy post in the guise of a technical analysis. [...]

The OP admits that the purpose was provocation. There's a word for people who engage in that kind of behavior online. That word originally denotes a fictional creature often told about in our old fairy tales.

The OP's subsequent behavior, with rather aggressive replies to rational arguments, doesn't weaken that hypothesis.