ISO Settings on DSLR's

I am wondering if anyone has any good advise on how to adjust ISO settings for underwater. I understand that the lower settings (ISO100) provide less noise but longer exposure times. And vise versa with the higher settings. My question is what settings seem to work best for underwater.

Does everyone shoot at the lowest possible setting? Or is a higher setting the standard for crisper pictures and faster shutter speeds?

At what point does the noise become a factor in image quality?

I understand that the responses probably change with every scene, but I am just curious if there are any rules of thumb that I should abide by.

Thanks!

It depends on the camera. When shooting with strobes doing macro or close focus wide angle, there is usually plenty of light and it is easy to shoot at base ISO (100 or 200 on most cameras). Base ISO always gives the best image quality, so you should use it if you can. Which most of the time you can.

Higher ISOs are useful for situations with less light. Wide angle in darker conditions, for example. How far you turn it up depends on your camera - some cameras have excellent image quality at higher ISOs, older ones tend to penalize you more for turning it up. Most UW shooting situations can be dealt with at ISO 400, but there are occasions when 800 or even 1600 or more might be desirable.

But higher ISOs should not be used as a crutch for poor technique. When shooting with strobes for many subjects (not fast moving ones obviously) there is no problem to use slower shutter speeds if your technique is good.

Alex

But higher ISOs should not be used as a crutch for poor technique. When shooting with strobes for many subjects (not fast moving ones obviously) there is no problem to use slower shutter speeds if your technique is good.

 

Alex

Hi Alex,

I agree with you and would like to learn more, can you build on what you said and educate us a little bit more please. What are some of those techniques? I want to keep 2 or 3 things that I can manage and should always pay attention to do when I am in different situation where I should be thinking about increasing the ISO or shooting at slow speed, etc. What are those situation, what are some of those techniques I should pay attention to. Currently I shoot w/ Nikon D80, Ikelite housing and a pair of DS125. I shoot w/ Tokina 10-17 and still have a lot of tough time getting balance lighting, Tokina 12-24, don't use much anymore, Tamron 17-50, I like the 50 end a lot & not shooting at macro range so I don't use diopter in the 8in dome. I also shoot w/ 60mm & 105VR. Help me improve, that's my 2009 goal, I want to move up a notch !

Appeciated and thank you !

Dominic