Re: Determining SPT with gum Was: Gums a la Demachy and Puyo

From: Ender100_at_aol.com
Date: Sat, 15 Jul 2006 14:12:47 -0400 (EDT)
Message-id: <2dc.9fa0107.31ea8a1f@aol.com>

Hi Katherine,

I think you are referring to my blabbering about choosing a "reasonable"
Standard Printing Time with Palladium when there is a lot of self masking/printing
out and as a result, no merged steps on the step tablet—so that one isn't
pushing a lot of the image info into the shoulder of the H&D curve. This of
course is significant, since the circumstances I am describing is a single
exposure print with Palladium, so there aren't any additional coats to be applied
to achieve the final vision of the print.

I'm not sure what you mean below when you say "And I guess I don't see why
that makes sense."

I apologize in advance for my density—log 2.7

Mark

I would agree, that there are so many ways that one might
In a message dated 7/14/06 11:25:47 AM, kthayer@pacifier.com writes:

> Mark, this is related to the point I was making re gum.  For many 
> reasons, the "natural" exposure times for gum emulsions will vary 
> widely, even given the same light source and other protocol.  Setting 
> an arbitrary exposure time, whether you set it at the median of the 
> distribution of exposure times or at the lower end, as it seems 
> you're suggesting here for another process,  some emulsions just 
> aren't going to be comfortable with the arbitrary exposure time.  The 
> farther the "natural" exposure time is from the arbitrarily-chosen 
> "standard printing time" the more awkward and extreme curve will be 
> required to make that  emulsion print a reasonable print in the 
> unnatural exposure time.  And I guess I don't see why that makes sense.
>
> Katharine
>

Best Wishes,
Mark Nelson
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Received on 07/15/06-12:13:11 PM Z

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