Re: Monitor Calibration
Re: Monitor Calibration
- Subject: Re: Monitor Calibration
- From: Robin Myers <email@hidden>
- Date: Fri, 08 Dec 2000 20:35:38 -0800
- Organization: Robin Myers Imaging
Dear Mr. Proulx,
>
I recently read somewhere (might have been by Bruce Fraser) that
>
there's a case to be made for calibrating the mionitor to 6500/1.8 while
>
using a workspace profile that uses 6500/2.2. Something to do with
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monitor 1.8 offering better midtone seperation which more resembles print
>
while the higher gamut 2.2 workspace offers more tones to play with.
>
Hopfully someone can jump in to clairify my (mis)understanding of what I
>
read somewhere. Might even have been an earlier thread...
There are FEWER usable tones in a gamma 2.2 workspace (in 8 bits/channel) than
a gamma 1.8 workspace. This is due to quantization to 8 bits. A gamma of 2.2
produces 184 unique gray values and a gamma of 1.8 produces 202 unique gray
values. The distribution of these values is shown below:
Output Values
Gamma 0-63 64-127 128-191 192-255 Total values
-------------------------------------------------------------
2.2 64 51 37 32 184
1.8 64 56 44 38 202
As the gamma is increased, higher values are shifted down to lower ones where
quantization takes it's toll.
Robin Myers