RE: Finding device gamma
RE: Finding device gamma
- Subject: RE: Finding device gamma
- From: "CS Carl Stawicki (4211)" <email@hidden>
- Date: Tue, 20 Aug 2002 14:08:26 -0400
Here is what I do to find the approximate gamma of my scanner profiles. I'm
pretty sure this is accurate, but if someone disagrees, please let me know.
Find out what the L* value of 128RGB is. In an RGB document in PhotoShop
that has been assigned the profile in question, go to your color mixer and
input 128 r,g,b, and see what your Lab values are. The L* value should give
you an idea of the gamma. Use different RGB spaces with known gammas for
reference:
Gamma 1.0 = L*74
Gamma 1.8 = L*61
Gamma 2.2 = L*54
Gamma 2.47 = L*50
I have scanner profiles that range from L*50 to L*54 at 128, so my gammas
are in the lower 2's.
Carl.
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From: Darren Sheppard
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Sent: Monday, August 19, 2002 5:40 PM
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To: email@hidden
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Subject: Finding device gamma
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How can one find the gamma of a output device. Say for example the gamma
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of
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a lightjet.
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Regards
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Darren Sheppard
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