RE: Is Na2 that sensitive?

From: Eric Neilsen ^lt;>
Date: 11/29/05-09:14:17 PM Z
Message-id: <002301c5f55c$26eeaea0$3cfdfea9@D6RJ5R41>

Wholly Smokes batman? Four post before I even saw one of them? Raven,
Palladium is very slow at low humidity and faster at higher humidity. 50% to
65 % is relatively stable but you will see changes. I don't see your
coating and drying techniques. Maybe they are waiting in the server to be
delivered after the new year.


If you see radical changes in any part of your process, consider small
incremental changes. Idea that the Na2 has no recommended dilution seems
curious as a drop of 20% is quite a boost. B&S gave you no directions?


Eric Neilsen Photography

4101 Commerce Street, Suite 9

Dallas, TX 75226



From: Clay []
Sent: Tuesday, November 29, 2005 5:33 PM
Subject: Re: Is Na2 that sensitive?


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:


I posted this (below) on Mark Nelson's PDN Group, but I'm hoping to get a
wider response here at ALT-Photo.



Raven Weiss <> wrote:

From: Raven Weiss <>
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 your 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.

Mike wrote:

Na2 is very sensitive.... I am not sure how you are measuring, but it is
possible 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

Best Wishes,
Mark Nelson

In a message dated 11/29/05 1:07:37 AM, 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
> (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

Mark Nelson
Precision Digital Negatives

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Received on Tue Nov 29 21:14:56 2005

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