What underwater setting for S 40

[ScubaSteeeve]

What is the best mode to shoot underwater in the dark waters of the North West w/o a strobe. Also, how exactly is the auto focus used?

[reypascual]

I am not familiar with the North West, but for dark waters (low light conditions) I get the best result when I use CLOUDY as the White Balance setting. I also don't use a strobe so sometimes I get the "snow" problem when debris and sand reflects the flash.

I also tried using custom white balance by shooting something white first and then shooting the subject but the pictures came out red. I don't get the same results on land though.

[JamesG]

I find that for 8 times out of 10, the internal strobe of the camera puts backscatter in the shot. This increases more and more the further away the subject is.

As for the evaulative white balance, you must remember what the water is doing to the light. You lose about 40% of red through every 1m the light travels.

So if you're using a strobe then the loss of red is 2x the distance from you to the subject, while if you're using available light, it's depth + distance to subject. When you do a white balance, keep all that in mind and it should turn out... None of mine have ended up too red, except when using a white balance for available light with the flash on!

As for modes, I'm usually in P or Av, switch the flash and macro modes when i feel like it, and switch between evaluative and cloudy/auto white balances. I also shoot in RAW so I can play around with white balance later. (If you shoot a couple of "white balance" photos of all the various types you need at the start of your dive, you can snap away without worrying about it and fix it later when converting the RAW files...)

Hope that helps!
James