Re: Off topic: banding in gradients
Re: Off topic: banding in gradients
- Subject: Re: Off topic: banding in gradients
- From: email@hidden
- Date: Thu, 7 Dec 2000 08:15:56 EST
In a message dated 12/6/00 6:46:31 PM, email@hidden writes:
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When I make grayscale gradients in Photoshop 6 in Adobe RGB mode the image
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contains banding on my monitor. I messed with it in grayscale and lab modes
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too with no betterment. Many people on the forum concurred with me, and
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the
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consensus from this group was to add noise to the gradient to meliorate
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the
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situation (but this doesn't give me the nice smooth grads I'm looking for).
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Others said they don't see the banding at all in such gradients and it
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must
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be a display card situation. We all agreed that we were viewing the
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gradients with our monitors set to millions of colors (my situation is
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a
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Lacie electron 22 blue, Mac G4 (AGP graphics) w/ 16 meg video RAM, system
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9.04, PS6).
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I printed my gradient as a test, but frankly on my Epson 1270 there is
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such
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color shift and non linearity of output across this grayscale gradient
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it's
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hard to be sure, but I think there is in fact less banding in the print.
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I get a nice smooth gradiant across 1600 pixels on the monitor from black to
white, but if I enlarge the image until I have only about ten steps on screen
I can detect slight tiger stripe banding throughout much of it (probably an
optical response the the steps), and have a posterized band at 90 percent. I
do not attribute all of this to the file itself, as the eyedropper moves
smoothly through most of it, but the band at 90% is real, and the eyedropper
will read the noisy transition zone as 89% and 90% values as shown on the
monitor. Chris Cox spent some time building smoother splined gradiants into
Photoshop a while ago (for v5 I believe?) but no one is claiming they are
perfect. I regularly use files containing all 256 levels of RGB gray in my
work, and I find Epson printers capable of printing output that defines over
200 steps, which is better than what my monitor can do, displaying the same
file.
C. David Tobie
Design Cooperative
email@hidden