The Sunday Times Travel Magazine


walkeja

Link Posted 05/03/2013 - 16:05
Has anybody seen the latest issue of the above?
Reason for asking is the section called "Photography Mastercalss", which this month is about underwater photography. There are some comments made by the photographer that I do not understand, e.g. "I used a slow shutter speed (1/80) to avoid any blur from his movement."
That, to me is illogical, but I don't know anything about underwater photography. Is what he has said true?

Thanks in advance.
Pentax K1-ii and MZ6
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steven9761

Link Posted 05/03/2013 - 16:45
Main reason why he'd use that shutter speed is because of light diffraction when submersed, I guess. I never really paid too much attention to the metadata on my photos when I used my Optio when I was snorkelling in Thailand, but I'm guessing that above the surface (with very strong sunlight) the shutter speed would have been at least 1/500, if not 1/1000, but underwater, I'd expect it to drop to about 1/125, or 1/80 caused by that diffusion. 1/80 would be a "fast" shutter speed underwater, I think.
Last Edited by steven9761 on 05/03/2013 - 16:45

gartmore

Link Posted 07/03/2013 - 08:02
I just checked some pictures from my Optio S50 (Marine housing and 'underwater' set from Scene menu) and they all seem to be around 1/80 to 1/100 and very bright sunshine above water. Not going to hurt my brain by working out why!
Ken
“We must avoid however, snapping away, shooting quickly and without thought, overloading ourselves with unnecessary images that clutter our memory and diminish the clarity of the whole.” - Henri Cartier-Bresson -

steven9761

Link Posted 07/03/2013 - 08:27
Ken - I think the scientific answer is light diffraction - light travels at a different wavelength through water than it does through air.

gartmore

Link Posted 07/03/2013 - 09:19
I cant see that that affects exposure. It affects focal length by making lesnses appear longer than they are.
Ken
“We must avoid however, snapping away, shooting quickly and without thought, overloading ourselves with unnecessary images that clutter our memory and diminish the clarity of the whole.” - Henri Cartier-Bresson -

johnriley

Link Posted 07/03/2013 - 10:06
Exposure is affected because the water absorbs the light, so it's darker down there. Red is absorbed quicker, so everything tends to look blue.
Best regards, John

steven9761

Link Posted 07/03/2013 - 10:09
Ken - the following link probably explains it better. Paragraph 2, sentence 1 explains what I was meaning, a bit better than I could have explained it. Basically, if light takes longer to reach an object in water than it does in air, then something has to give - in this case the shutter speed needs to be slowed down to capture the information.
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