Re: scanner density-value relation

From: Don Bryant <dstevenbryant@mindspring.com>
Subject: RE: scanner density-value relation
Date: Wed, 09 Mar 2005 09:05:31 -0500

> You can use Vuescan software to obtain log density values directly.

Yup, I've been using it for long enough to know that. The reason I
wrote a program is to average out a certain measurement aperture to
reduce noise and perturbation from fine surface texture (especially
with prints). Also, I could have my own calibration table based on the
raw scans of a calibrated step tablet. (The program I wrote was a bit
easier than making a vocoder program so that I could make a funny
greeting message for my voice mail, and go to karaoke to sing
something stupid... remember Roger Troutman & Zapp?)

> However it has been my experience with several different Epson
> scanners as well as a couple of Microtec scanners that the DMAX
> ratings are way way over inflated.

...and the quantitative comparison of which was the center of my
original question.

> IMO, you are wasting your time trying to do serious densitometry without a
> densitometer. A good used XRITE 810 isn't that expensive.

The point well taken. 810 would do.

--
Ryuji Suzuki
"Well, believing is all right, just don't let the wrong people know
what it's all about." (Bob Dylan, Need a Woman, 1982)