On Apr 12, 2015, at 1:22 PM, QuadtoneRIP@yahoogroups.com wrote:
Hello,
Here's a Dropbox link to the 21-step greyfile supplied with QTR:
https://www.dropbox.com/s/7gszzza0mcpod99/21step.tif?dl=0
I wan to measure the density of each step. I note there are three areas to this scale. The top area is a continuous scale, from dark to light. The second, or middle, area shows the steps but with a sort of "scallop" to each patch. The bottom area shows the steps separated by thin white lines, and the steps are more uniform than than the second area's steps.
It seems to be me I should be measuring density from the third, bottom, area to get a more representative reading. Is that correct? If so, just wondering why that middle area has "scalloped" steps. You may have to enlarge the view to better see what I mean.
TIA,
Paul
Message
Re: [QuadtoneRIP] question re: greyscale
2015-04-12 by Myron Gochnauer
You will discover that only the top row is a smooth scale from black to white. The second and third rows make uniform steps as indicated by the dividing lines. The apparent change in density within each step is a perceptual illusion, not something
“objectively” measurable.
It is really hard to believe that what you are seeing is an illusion. I keep going back and putting the eyedropper on the “light” side of a zone and then carefully moving it to the “dark” side. . . and yes, the reading a precisely the same. Good
grief!
Myron