Dodgy photos (quality wise)

[Truffle]

Hi guys,

A little critique would be really useful , go easy on me though, although i have been taking photos for a couple of years i haven't got a clue what I am doing, technically speaking, i.e depth of field apperture and shutter speed and how they relate to each other, if they do.

Here are some phots that I have taken, maybe you could spot a re-occuring problem with them:

http://www.hurstpointyachts.com/Avatar%20Page/hequii640.jpg

http://www.hurstpointyachts.com/Avatar%20Page/Scobinancustrus%20auratus%20640.jpg

http://www.hurstpointyachts.com/Avatar%20Page/eureka640.jpg

Thnks for you help

Tristan

[alanhill]

Nice photos and very nice fishes :-D

There isn't too much wrong with these photos, but you are right to look at them critically.
They show the limitations of using on-camera flash, you get contrasty images with prominent shadows.

If you're using flash, you don't need to worry about shutter speeds, because the flash is so rapid that everything happens while the shutter is fully open. The aperture is the size of the hole in the lens that lets the light through, like the pupil in your eye. The smaller the number, the larger the aperture, so more light enters the camera.
Large apertures only give small depth of field - for example if the eye of the fish is in focus, the mouth and gill cover might be out of focus if the depth of field is small, which is why the experts use lots of light so they can set a small aperture (f/8 down to f/16 or f/22) and why they prefer to take photos when the fish's body is abolutely parallel to the focal plane of the camera (in other words to the CCD or the film).

Alan

[hir0]

read the article posted here (http://aquatic-photography.com/forum/showthread.php?t=1588&highlight=article+exposure) if you can find the time.

[Truffle]

Thanks Alan

Someone said that it might help to take photos with a higher ISO, not sure what that is, but when i raised it ro 800+ on my camera, a signal comes up saying that only 1MP resolution can be used for these settings. Why is this so?

Has anyone got any idea?
Thanks

Tristan