Re: Is Na2 that sensitive?

Have you seen the chart "Standard Negative Contrast Ranges for
Palladium Prints Na2 (Sodium Chloroplatinate) Method" at Dick Arentz'
web site? If not the direct link is http://www.dickarentz.com/na2.html

The amounts suggested by Arentz have worked very well for me as a
guide in the past when printing with the Na2 method.

Sandy

>Hello Clay,
>
>Thanks for your insight on Na2 concentrations in your process.
>
>I ran a quick print test tonight. I brush coated paper
>(Platinotype white from B&S) using 1.7mL of FO + 1.5mL of Pd sol'n
>#3 + 7 drops of ~1% Na2 solution (from a serial dilution of the 20%
>from B&S). My thinking is that if I keep the number of drops high,
>then the drop sizes (and amount of Na2 delivered) will average out.
>
>I also coated another sheet of the same paper with the same brush &
>the same chemistry but without any Na2.
>
>I exposed both at the same time using a 101-step tab & Mark Nelson's
>Tonal Palette in my Nuarc 26-1K.
>
>Both prints showed tonality all the way down to the B=0 square (R=0;
>G=255), so I'm concluding that 7 drops of 1% Na2 is too little
>contrast agent and my previous conce ntratio of 3 drops of 20% Na2
>is too much. I'll test again at an intermediate concentration.
>
>Sincerely,
>Mike
><http://www.ExpsoeTheShadows.com>www.ExpsoeTheShadows.com
>
>
>
>
>
>
>
>
>
>Clay <wcharmon@wt.net> wrote:
>
>This is one heck of a lot of Na2 for these volumes. I am using 1
>drop of 2.5% Na2 in the same sensitizer volumes for my digineg work.
>I would cut this stuff 1:7 (2.5%) and just use a drop or two of that
>strength.
>
>On Nov 29, 2005, at 11:00 AM, Raven Weiss wrote:
>
>>Hello,
>
>I posted this (below) on Mark Nelson's PDN Grou p, but I'm hoping to
>get a wider response here at ALT-Photo.
>
>Sincerely,
>Mike
><http://www.exposetheshadows.com/>www.ExposeTheShadows.com
>
>Raven Weiss <<mailto:ravenweiss@yahoo.com>ravenweiss@yahoo.com> wrote:
>
>To: <mailto:PDNPrint@yahoogroups.com>PDNPrint@yahoogroups.com
>From: Raven Weiss <<mailto:ravenweiss@yahoo.com>ravenweiss@yahoo.com>
>Date: Tue, 29 Nov 2005 08:25:45 -0800 (PST)
>Subject: Re: [PDNPrint] Is Na2 that sensitive?
>
>Hello Mark,
>
> Thanks for your quick response (below).
>
> Looks like you are using a serial dilution method, which makes
>sense if Na2 concentrations need to be that precise. Unfortunately,
>I don't have a pipette, just an eyedropper. In yo ur experience,
>will it be sufficien t for me to serial dilute as you suggest but
>use an eyedropper if I'm using enough Na2 that equates to a
>concentration in the middle of Dick Arentz's chart?
>
> Also, if I humidify my paper prior to exposure, will I drive this
>(film speed of the paper) towards repeatability? Or, will I just
>introduce another variable? Specifically, the relative humidity is
>around 10-15%. Does this variability cause a change in paper speed
>- and, does humidifying the paper to anything above 50% keep the
>paper speed constant?
>
> I hope I'm making my question clear.
>
> Sincerely,
> Mike
> <http://www.exposetheshadows.com/>www.ExposeTheShadows.com
>
>
>
><mailto:Ender100@aol.com>Ender100@aol.com wrote:
> Mike,
>
>Na2 is very sensitive.... I am not sure how you are measuring, but it is
>possib le that your problem could relate to that. Have you seen
>Dick Arentz's
>chart for Na2? It is availab le on his website.
>
>I dilute the Na2 by cutting it with equal parts of distilled water... then I
>repeat to get 20%, 10%, 5%, 2.5% & 1.25%. I do this with a pipette.
>
>Also, humidity can vary speed... make sure your humidity and drying times are
>constant.
>
>Best Wishes,
>Mark Nelson
>
>
>
>
>In a message dated 11/29/05 1:07:37 AM,
><mailto:ravenweiss@yahoo.com>ravenweiss@yahoo.com writes:
>
>
>> Hello Folks,
>>
>> I've used the PDN system with success late last year to produce Pd-toned
>> Kallitypes.
>>
>> Now, I've been trying to create an adjustment curve for Palladium using
>> Na2 contrast agent. Finding the correct exposure time was easy. However,
>> getting the correct color density choice (choosing the first "paper white"
> > square) has been very difficult. I'm getting everything between
>B=30 and B=70
>> (with R=0, G=255) with th e same (I think) level of Na2.
>>
>> Specifically, I'm using 1.7mL of FO and 1.5mL of Pd sol'n#3 and 3 drops of
>> 20% Na2. All chemicals are relatively new & clean - from Bostick &
>> Sullivan.
>>
>> The drift in color density choice is causing wide variations in the
>> 101-step tonal palette, as you can imagine.
>>
>> I'm thinking of diluting the Na2 by 10 fold and using 10X of this dilute
>> solution - hoping that the variability will average-out and give me
>> reproduceable results. Any hints on how else to proceed?
>>
>> Sincerely,
>> Mike
>> <http://www.exposetheshadows.com/>www.ExposeTheShadows.com
>>
>>
>
>
>
>
>
>Mark Nelson
>Precision Digital Negatives
>
>
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Received on Wed Nov 30 07:43:50 2005