Underwater light absorption
Posted 24 May 2005 - 07:15 PM
Are there any formulas or rules of thumb to determine how much more light it will take to light a subject underwater?
Posted 24 May 2005 - 07:34 PM
The ASC manual probably told you about the drop off in the red spectrum at about 15ft. This can be largely corrected via the use of a red filter.
I have shot lots of underwater film and video in the Caribbean. The water visability was excellent up to 100 ft and it was always a bright sun with clear skies. At 65 ft you'd be surprised how bright it is. Under those conditions I often will not use any electrical light because on wider shots it creates a "glow" in the centre of frame that looks un-natural. I'm sure you've all seen this look in shows about ocean life. Up close the lights work better if they don't have to cover as wide a space.
So I'd have to say it depends on what type of look you want and the other characteristics I mentioned above.
PS: If you're shooting 35mm underwater then the Kodak 250D works very well.
Posted 26 May 2005 - 04:44 AM
watchout if you have to focus, marks are different from air marks.
Posted 26 May 2005 - 11:25 AM