RE: Best CI for process

From: Sandy King ^lt;>
Date: 10/03/05-03:22:07 PM Z
Message-id: <a0602041ebf674fe1f8a3@[]>

Yes, but based on your previous explanation of how you figure the ES
the reason for our different count is now very obvious. There would
typically be at least three or four additional steps from first
shadow value I count as opposed to the way you count.

However, assuming that you are printing with digital negatives your
method of counting makes sense because we can adjust the curve to
extract every single bit of Dmax, all the way to the last step. When
printing with digital negatives my ES is essentially the DR since I
am using every single bit of density in the negative, and it is quite
a bit higher than when printing with continuos tone negatives.


>Only 12 ? wow
>Eric Neilsen Photography
>4101 Commerce Street
>Suite 9
>Dallas, TX 75226
>From: Sandy King []
>Sent: Monday, October 03, 2005 4:00 PM
>Subject: Re: Best CI for process
>When I evaluate a step wedge print made from a continuous tone step
>wedge I count the steps from the first density over pure paper white
>to the first shadow step that merges with the next one. Using the
>pure palladium mix I described earlier I usually get about 12
>steps, which works out to a exposure scale of 1.80.
>>Content-type: text/html; charset=UTF-8
>>Content-language: en
>>Hi Eric,
>>Just for reference, how do you figure your exposure scale? I know
>>this sounds like a dumb question, but I have seen it defined
>>differently by different people. Do you include the first paper
>>white step also?
>>Sandy, could you also respond to this question?
>>Best Wishes,
>>Mark Nelson
>>Purchase the eBook & PDN System for Your Own Custom Digital
>>Negative Workflow @
>><>Precision Digital Negatives
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>>In a message dated 10/3/05 1:03:42 PM, writes:
>>Sandy, I don't use or test a pure palladium. The smallest amount of platinum
>>that I add is 15% of total metal salt solution. I make my own ferric oxalate
>>and use a palladium solution that is mixed at 5 g NaPd with 3.5g NaCl to
>>make 40 ml. This makes a .7 M solution to match my .7 M ferric oxalate. The
>>Platinum is a .457M solution in potassium version and .7M when I can get the
>>ammonium version. The molarity may be off by +/- .015 as these are from
>>memory but I don't think so.
>>My exposure scale for the 1.0ml FO, .15ml K Pt, and .85ml Na Pd, is 2.45.
>>I make most of my exposures after a 10 minute dry@ 100F and a 30 minute
>>humidification @60% RH. I process in Potassium Oxalate at both room temp of
>>70 and heated to 90F. The exposure test that produced the ES above was
>>processed at 70F.
>>These test were also performed with Starphire glass in the contacting
>>printing frame.
Received on Mon Oct 3 15:22:27 2005

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