underwater photography, how are the images so clear?

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paul.fr

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How do photographers get clear, undistorted pictures when underwater?

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Offline Karen W.

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underwater photography, how are the images so clear?
« Reply #1 on: 12/01/2008 16:47:57 »
Perhaps the equipment, underwater cameras use the water as a lens of a type.. couldn't water act as a lens,it reflects sort of .. maybe I am off Hee hee.. but am wondering if thats possible..???

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Offline techmind

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underwater photography, how are the images so clear?
« Reply #2 on: 12/01/2008 21:47:06 »
Usually the waterproof enclosure has a plane (perfectly flat) piece of glass separating the water outside from the air inside. This does not change the focus of the camera in the drastic way that putting a curved surface (such as your naked eye) directly in water.

It's just the same as when you wear a pair of goggles for swimming or a facemask for diving - you have a planar (flat) air/{glass or plastic}/water interface.

Owing to the refractive index of water, and the well-known foreshortening of depth, the photographer will still have to focus about 2/3rds closer than the real distance (i.e. they focus on the apparent depth) -- or whereever it looks sharp.
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lyner

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underwater photography, how are the images so clear?
« Reply #3 on: 13/01/2008 23:41:35 »
It's really dependent to the amount of stuff floating around in the water. When there is any cloudiness, the pictures are very poor. Lighting has to be just right; flash photos can suffer from back-scatter so your flash sources have to be on long arms, well off-axis..
Most of the best pictures you see are cheats; they are done in tanks with filtered water -in the same way that all the close-up pictures / movies of small mammals and invertebrates are shot indoors in artificial conditions. It's all fitted into the wild shots with clever editing.

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Offline Karen W.

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underwater photography, how are the images so clear?
« Reply #4 on: 14/01/2008 16:31:38 »
Thats interesting!

"Life is not measured by the number of Breaths we take, but by the moments that take our breath away."