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Old 08-19-2010, 06:42 AM   #24
Ben Thornton
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Posts: 900
Karma: 779635
Join Date: Jan 2010
Location: UK
Device: Kindle 3, iPad 2 (but not for e-books)
That's interesting. I hope that I'm not breaking any rules by quoting it:
Quote:
Old (white) Kindle DX (6 months old):
white area density = 0.46, Lab = (65.8,-2.3,0.6)
black area density = 1.30, Lab = (26.6,-1.0,-2.2)
contrast in density = 0.84, contrast in lightness = 39.2

New (graphite) Kindle DX:
white area density = 0.42, Lab = (68.2,-2.4,0.9)
black area density = 1.58, Lab = (18.5,-0.1,-3.6)
contrast in density = 1.16, contrast in lightness = 49.7

I used a Datacolor Spectrocolorimeter model 1005. "Lab" is a color space measurement; the "L" stands for lightness--it matches the number on the box when you buy copier paper.

I have no idea how to turn these numbers into a percentage contrast. But from density numbers alone, white is a little whiter, black is a lot blacker.

EDIT: I've measured the paper and ink densities for some books I have, for comparison:
trade paper: ink = 1.69, paper = 0.07 (contrast = 1.62)
new pulp: ink = 0.87, paper = 0.19 (contrast = 0.68)
old pulp: ink = 0.79, paper = 0.24 (contrast = 0.55)
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