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......
The effect you observed from using color filters is presumably because
graphic arts film is blue-light sensitive so a yellow filter would cut
down exposure.The steps themselves, not just D-max & D-min, change with
exposure, & it's possible some development changes were rung in at the
same time.
(My students also assume that VC filters will change contrast on film,
but they usually complain that it doesn't, tho every so often one swears
it does.)
I don't see the price info posted now, but as I recall, assuming the "?"
that printed here in front of the number represented a dollar sign, the
Agfa 30x40 cm film you cite costs -- something like $5 a sheet in northern
Europe .....Is that possible? The same or a similar film by Agfa (made in
Belgium) is sold by Palladio in this country for about $3 per 30x40cm
sheet.
And that's the only advantage of lith film, unless you want really
industrial strength high contrast. A slightly larger sheet of lith film
(12 x 18 inches) costs about $1 a sheet from Freestyle in California, tho
attempting to import it to Europe would be slow and costly.
My tests, BTW, show that the lith gives a better scale in D-76 than
Dektol (thanks to S. Wang for the suggestion) and I have had good results
getting it VERY soft for gum with a soft-working glycin developer.
And along in here, as I recall, someone mentioned Selectol. If they meant
Selectol Soft, it's no longer made. I forget whether Selectol is still
made, but don't think it would be any better than Dektol in any event.
Judy
PS. I have a long-in-work book "Negative Thinking" about some of these
issues, guess I better work faster.