Is this exposure scale derived by counting 21-step Stouffer tables discernable
steps and multiplying by .15? The reason I ask is that I'm betting Sandy is
using the BTZS plotter program, and the way it calculates exposure scale is
predicated on picking a maxium black value. I know that Dick Arentz uses 90%
black for his work....
Quoting Eric Neilsen <e.neilsen@worldnet.att.net>:
> 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.
>
>
>
>
> Eric Neilsen Photography
> 4101 Commerce Street, Suite 9
> Dallas, TX 75226
> 214-827-8301
>
>
Received on Mon Oct 3 12:10:19 2005
This archive was generated by hypermail 2.1.8 : 11/07/05-09:46:18 AM Z CST