"Steve Goldstein" wrote

I was recently doing some step-wedge testing and noticed
that anything higher than grade 3.5 looked prettmy much the
same. Here are the details Zone VI cold light head
Zone VI intensity controller

I take it you have the ZVI single tube head and the
'cold light stabilizer' box with 'lamp intensity' and
'drydown' knobs.

Kodal Polymax filters (relatively new, high contrast barely used)
Luminos Flexicon VC (= Kentmere Fineprint VC, I think), both in
fiber and RC, also Forte Polymax fiber

Some possible causes:

1) Papers and filters are designed together: Kodak filters for
Kodak papers, Ilford filters for Ilford paper ... I don't know
what filters are best for Forte and Luminos [And Luminos can
be _anything_, though if marked UK then it is probably
Kentmere]. I would suggest giving Ilford filters a try.
Looking at Forte's web site may give recommendations for
filters.

2) Old paper looses contrast. Paper can sit on a dealer's shelf
for years.

3) Cold light heads will shift spectrum with temperature, try
leaving the enlarger on for 1/2 hr before printing.

4) Cold light heads and VC papers have never gotten along very
well. However, the problem is usually that no low grades can
be achieved.

5) Try developing for 5 minutes. VC and many graded papers
are made from two or more emulsions with different contrasts.
If the high contrast emulsion isn't developing fully then the
print looses contrast though it may have full blacks. Try
Dektol 1:1 as a check. Some papers and some developers
have trouble developing fully: Forte and Arista developer
are a bad combination - after 5 minutes the paper still
hadn't developed fully. Forte graded will take 5 minutes
in D-72 [Dektol] to develop to completion.

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.nolindan.com/da/index.htm
n o lindan at ix dot netcom dot com