Re: Pyro processing/Densities of a Stouffer step wedge

Cor Breukel (cor@ruly46.medfac.leidenuniv.nl)
Wed, 14 Jan 1998 13:10:34 +0100 (MET)

On Wed, 14 Jan 1998, DEREK WATKINS wrote:

> The advantage of Pyro is that it produces a yellow stain in proportion to
> the silver image. Because most alternative process prints are exposed to
> UV, this yellow stain acts as extra density and effectively gives you the
> higher contrast negative you need for alt prints.

Could Pyro help me out on the following?: Some time ago I bought quite
some "obscure" 4*5 inch film: Efke PL100M made in Zagreb, Croatia,
formally made in Germany, known as ADOX. I am not able to get a higher
Dmax (corr.) of about 1.7. I used D76, D19 and Xtol finally undiluted and
for max. of 14 min (incedentally: with the 35 mm version of supposely the
same emulsion I obtained Dmax of around 3!). So could Pyro boost my Dmax
for Alt. Processes?

An (slightly) related question: Can one "translate" the numbers/steps of a
Stouffer Step Wedge to the Zones of The Zone System i.e: Step number 5
eqquels Zone V ? I tend to think so: I took densitometer reading of all
steps, and step 5 reads (corr. for B/F) 0.66. One of my books gives a
corr. D for a greycard/Zone V as 0.70, so that seems to fit.

Cor Breukel

http://ruly70.medfac.leidenuniv.nl/~cor/cor.html
"The Infrared Gallery"
http://ruly70.medfac.leidenuniv.nl/~cor/ir-gallery.html