U of S | Mailing List Archive | alt-photo-process-l | Re: VueScan: (was: Re: Measuring DMAX

Re: VueScan: (was: Re: Measuring DMAX

Thanks and aplogies to those who responded and whose responses I didn't see earlier, like Don and Yves. I don't get all the posts all the time, and I have to keep remembering to go to the archives to see if there are posts I didn't get. Anyway, thanks much for solutions to the problem.

As to gum print DMax unlikely over 1.1, I've measured gum prints with DMax up to 1.8 with a densitometer, which matched the visual density as estimated by comparison to a Stouffer reflection density step tablet. But I had to give the densitometer back so I was intrigued by this Viewscan solution to reading densities in an easy and straightforward manner. Just now, (now that I can finally read one value) I looked at a gum print that was near at hand, not one of the ones that read as high as 1.8 before, but a one-coat with a somewhat lighter pigment mix; according to ViewScan the darkest areas read between 1.3 and 1.6. Marek reported DMax for one-coat gum prints at 1.4 recently, as I recall.

On Feb 1, 2008, at 11:05 AM, Katharine Thayer wrote:

On Feb 1, 2008, at 8:46 AM, Katharine Thayer wrote:

Thanks, but not true; my three numbers are all different; I've never gotten three identical numbers, either in 8 bit or 16 bit, or even in 1 bit! They generally range over 6 or 8 points, but sometimes as much as 12 or 15.

I was half asleep when I wrote this; by "6 or 8 points" I meant, like for instance a point I'm looking at now (in 8 bit black and white mode) that gives me these three values: .90 .94 .98.