There is a photographic myth with 18% grey. The myth is the idea that
your camera's meter assumes 18% grey, which is incorrect. Meters assume
roughly 12.5% grey (there is an ISO standard). Grey cards are 18% for
the reason graywolf explains, as well as due to intense lobbying of
Kodak by Ansel Adams (Who wanted 18% grey because it is 50% luminance
and right in Zone V). But overall, most scenes do indeed average out to
18% grey.
-Adam
graywolf wrote:
18% gray is not a myth. It is just that most people do not understand
where it comes from. If you go out and measure thousands of scenes
with an averaging meter, the average of those exposures will come out
to 18% gray. So 18% reflectance is an average value, where you want to
put that average value in your particular photo is up to you. It
certainly is not cast in concrete (which is usually near 18% gray, by
the way <grin>).
graywolf
http://www.graywolfphoto.com
"Idiot Proof" <==> "Expert Proof"
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Bob Shell wrote:
On Dec 3, 2005, at 9:26 PM, Rob Studdert wrote:
I think blanket statements regarding optimum print resolution are
pretty
useless as the printer in concert with the driver its settings and
the paper
type determine the optimum print resolution. Also I never
experienced problems
printing images with resolutions that weren't multiples of the
natural printer
resolution on any inkjet print systems.
I agree. The idea that you have to use multiples of the printer's
stated resolution (itself a mythological beast) is another
photographic myth, like 18% gray.
Bob
