> >>>>> On Sat, 9 Sep 1995 09:12:42 +1000, Judy Seigel <jseigel@panix.com> said:
> >> >If your film really changes contrast with color filtering (does it say
> >> >that on data sheet or could this be simply effect of more or less exposure?)
> >> >get two freezers full......
>
> >> Thomas Blomqvist replied:
> >> I have been using Gevarex in workshops only so I haven't even seen a data
> >> sheet, but I have seen the densitometer readings change. And I'm talking
> >> about density ranges here, not max or min densities only.
>
> > I've been waiting for someone else to address this -- everyone
> > is strangely silent, end-of-summer torpor? busy with acrylic?
> > As far as we are told in the known universe (unless Agfa has a stealth
> > film in Europe), contrast control in continuous tone film is achieved by
> > exposure and development, as the zonies on this list should have
> > declared. They are not formulated for variable contrast filters......
>
> Without knowing the specifics of Gevarex, VC filters would allow contrast
> control if the product's emulsion was similar to that of a VC printing
> paper while applied to a clear (not RC or baryta) base.
>
> Pete
>
The making of enlarged duplicate negatives is essential for some of the
historical processes since most of them require contact printing.
I am in New York City and of course I fall under the control of the Kodak
yellow box.
I have found that the best technique is to first contact print the small
neagtive onto one of the black and white lantern slide slow emulsion
films.THis will give you a good brilliant positive and it is capable of
contrast control by the usual methods.
Having accomnplished this you can now enlarge this to the size you want
using Kodak Commercial Film. You can work through these steps in the
comfort of a fairly bright red light. Your new negative will be fine for
Carbon printing, oil transfer and just about any contact printing process.
Tracy Diers NY