Tony Duell wrote:
Has anyone ever tried them for flim[sic]
photograhpy[sic]? THe data sheets I looked
at showed a fairly continuous output spectrrum[sic] (unlike the pure colour
LEDs, of course), which could presumably be filtered into something that
looked like daylight to colour film.
As long as the output color temperature of the light is fairly
consistent, it doesn't matter much if it skewed to one side or another.
Well, it pmatters on reversal film, in that you can't correct it later.
But of course you can use colour correction filters when you take the
photograph.
But only if the light spectrum is relatively continuous. No way can you
correct the ligth from a low-pressure sodium lamp, or LEDs other than
white ones.
We shoot gray cards to achieve a neutral white balance.
When you deal with mixed lighting scenarios inside a house, you're
basically dealing w/ the same thing. You might have some filtered
daylight through a window, some incandescent bulbs, and so on.
When you have mixed lighting, it's imppossible to get the colours spot-on
(unless you filter the light sources). Whether that matters depends on
what you are photographing and why.
My idea for usiong white LEDs is a shadowless light source for macro
work, which in my case is likely to be bits of computers, calculators,
etc. The colours don't have to be perfect (I am not going to try to
match them later), but of course I don't want a strong overall cast to
the picture.
-tony