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There is another problem with images on the web: color
reproduction. The colors you see are determined by the
display hardware you are using, not the colors that I
scanned. Most of my images are very uncritical of color, but
all pictures are sensitive to the tonal scale used
(the digital assigment of the shades of gray between black
and white). The pictures on this web site are encoded using
the sRGB proposed web standard which utilizes an approximate
gamma 2.2 transfer function.
If your monitor is calibrated to this already, great. Otherwise you can use the tools below to make a crude calibration using the brightness and contrast controls on your monitor.
So, here's the brute-simple calibration routine:
Look down the scales to find the one where you can still
make out the steps. You will probably find the steps easier
to discriminate at some specific position along the scale.
If the steps all blend about equally, congratulations, your
display is visually equidiscriminant and you are
unlikely to notice contouring artifacts. This is not the
goal however, read on.
"Equidiscriminant" is not the correct tonal scale for the images. The more important indicator is what position along the scale represents "middle" gray. The following tool will help get this right:
If your display matches the sRGB tonal encoding used in my photos, the gray patch on the right will match the average gray produced by the tight checkerboard pattern (blur your eyes or step way back to blend the pattern to a uniform gray). If you are viewing on a Macintosh, the pattern may look closer to the left hand gray patch.
I encourage everyone serious about viewing and working with images to obtain monitor calibration software. It's the first step toward looking at what the author intended us to see!