At 09:12 9/9/95 +1000, Judy Seigel wrote:
>
>On Thu, 7 Sep 1995, I wrote:>
>> >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......
I am not the right person to scientifically prove why this is happening, but
I have right now a photo magazine article from 1985 and a book from 1995 (
Gravyyrioppi by Taneli Eskola & Kari Holopainen, ISBN 951-9384-73-1/ISSN
0782-1778) in front of me, backing up what I have been saying. The text (in
Finnish,) is about Photogravure techniques and is published by the Art
College of Helsinki. Following is a translated part of that text (page 36,
my translation):
"Agfa Gevarex 230 P is a low contrast, continuous tone film with variable
gamma. It is possible to affect the contrast to a certain amount with the
light of a color enlarger. If larger contrast ranges are desired dense color
separation filters are used; yellow light will raise the contrast and cyan
will lower the contrast. Gevarex has proved to be an excellent material, but
sometimes it can be difficult to achieve a contrast high enough. Then you
can try a high-contrast graphic film developer"
>(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.
As far as prices goes, ANYTHING is possible in northern Europe :-)
///////////////////////////////////
| Thomas Blomkvist troo@xgw.fi |
| Finland ******* |
|---------------------------------|