RE: old UV tubes less contrast?

If a negative prints well with Grade 0 paper, that doesn't necessarily
mean it will print well with Vandyke. Because AFAIK, Vandyke's density
range requirement is around log 1.9 (assuming 0.3 b+f, that makes an
absolute dmax of log 2.2 on the negative!) and if I'm not wrong, you
won't be able to print such a negative with good blacks even on Grade 0
paper.

Double coated and gold toned Vandykes are pretty good dmax-vise IME.
Almost as good as (if not better - depending on paper brand) a
silver-gelatine print on matte paper...

What is your enlarged-negative-making method? Or, do you use in-camera
negatives? See "Less Is More" article in Unblinking.eye if you enlarge
your negatives in darkroom (and have access to ortochromatic film + not
afraid of dealing with sulfuric acid and potassium dichromate), Mark
Nelson's "Precision Digital Negatives" or Dan Burkholder's "Making
Digital Negatives for Contact Printing" are the books you should read
for making negatives digitally. You don't need a densitometer (having
one is definitely a plus, but it's not a "must"), a scanner will do the
job (I measure densities using a scanner - as described in Mark's book).
A couple of Stouffer 21-step or Mark's 31-step tablets would be very
helpful (having them is almost a "must" - makes your life a lot easier).

Hope this helps,
Loris.

-----Original Message-----
From: david drake [mailto:daviddrakephoto@sympatico.ca]
Sent: 03 Mart 2006 Cuma 04:26
To: alt-photo-process-l@sask.usask.ca
Subject: Re: old UV tubes less contrast?

...
I think your probably correct in that the negative needs just a little
more contrast. I don't have a densitometer and, therefore, judging a
negative of good contrast for the process is difficult. From a previous
posting I did learn that contact printing them on RC paper at grade 0
should produce results approximate to VDB prints. However, this is
probably a good starting point; as there are many other factors at play.

I'm getting good whites with no fogging. I guess what I'm really after
is more dmax while retaining good mid and higher tones (more contrast).
It's difficult to know what this process is capable of when all one has
for reference is web images. Some of Wynn Whites images on the
Unblinking eye site have pretty incredible dmax.

I was concerned about the age of the tubes in the lightbox only because
it's in a co-operative darkroom I use and I have no idea how old they
are. I also remember reading somewhere that the really old bulbs produce
prints of less contrast, but perhaps this is not the case.

I would like to find a way of creating fairly consistent density in my
contact negatives. Perhaps a densitometer is the way to go.
...
Received on Fri Mar 3 04:32:27 2006