Ender100@aol.com
Date: 09/20/02-11:53:18 AM Z
Hi Judy,
The reason that the digital step tablet doesn't print the same number of
steps as a stouffer's is that you have different densities in the Stouffer's
film vs the digital tablet. The Stouffer's probably goes all the way up to
above 3.0, while the digital may not even make it to 2.0 density.
The reason that the steps don't look nice and smooth in their gradations on
the digital step tablet is that the printer is not linearized—i.e. you would
have to make a curve or profile the printer to get it to print a perfectly
linearized step tablet.
If you made a step tablet on an imagesetter, you would get more density, and
thus the capability of steps more similar to a Stouffer's. Digital film from
an imagesetter will render density between 3.0 and 4.0 I believe.
As far as doing a steptablet by using the posterize command goes, it's
probably fine for gum. (hehehehe just kidding) It will get you pretty
close, thought the steps may not be equal in size (if that bothers you).
Hope this helps,
Flauntingly yours,
Mark Nelson
In a message dated 9/20/02 1:36:27 AM, jseigel@panix.com writes:
<<
To all digital "experts" or wannabes:
I have, between catastrophes, been trying to generate enough info on
digital negatives (the first cause of the most hellacious upgrade in the
history of ones & 0s) for an article slated for the vaunted P-F #8. I
seem to be moving backwards, however, stumbling in well-covered ground.
For instance, here's how I made a 21-step for digital tests:
I made a ramp from zero to 100% in Photoshop, then posterized it into 21
steps.
(Even if you did this at 5% and 95% I doubt results would be much
different.)
So here's my question:
Why does it print fewer steps -- on each of 5 substrates I'm testing --
than the Stouffer 21-step I'm printing next to it.
And I mean by about a third.
And here's my other question -- the Stouffer 21-step shows lovely even
steps -- about 6, 7 or even 8, in various gum emulsions, depending on
length of the soak. My digital 21-steps from hell are, except for the ones
on mere vellum (feh!, kid stuff) wildly uneven -- sort of grand canyon
leaps at top, then squished at the bottom. (The vellum "curve" is quite
straight... but the material is otherwise problematic and I'm trying to
find something better.)
Sneers OK if info is good.
Judy >>
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