In message
, Don
Stauffer in Minnesota writes
On Mar 19, 11:39 pm, Pooua wrote:
http://web.mit.edu/neltnerb/www/artw...x.htmlfeatures artwork
illuminated by super-bright LEDs, but the photos do not accurately
reflect the colors of the lighting. The artist says that his camera
has trouble picking up the purple lighting, instead showing it washed
out, apparently because it is outside the normal color space of the
imaging sensor. Does that sound likely? What might a photographer do
to take better photos of these tricky lighting situations?

Here is yet another problem. We frequently do not perceive with our
eyes the true color of LED or laser light sources if we view them
directly. Some of the cones can saturate, really throwing off our
eyeball calibration.

Bayer mask cameras go haywire even more spectacularly with pure
monochromatic light. My old Kodak Dc-120 completely freaked out when
used to image an H-alpha narrow bandpass image of a prominence on the
sun. Even though it was a sub Angstrom passband red filter the image was
bright enough to saturate the red channel and put enough signal into the
green and blue through filter leakage in the cameras filters to give
bizarre results. I think it metered mainly on the green channel.

Digicams need to be deliberately underexposed on coloured lights or LEDs
to capture the colours otherwise they will wash out or worse turn some
other colour.

BTW If you think digicam rendition of the purple magenta line is bad you
should see some of the films. Certain flowers with strong purple flowers
present considerable difficulties in photographing accurately on film.

Regards,
--
Martin Brown

--
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