Thanks to a very good friend, who is internetted, we have had the possibility
to read some of the recent discussion about autochromes. Through him we would
like to tell you a little about our experiences of making "real" three colour
carbon double transfer prints from these wonderful colour plates, that might
be of interest for some of you.
We have done slide dupes, directly from the original as well as first
"pushed" them through the computer. We have achieved good results (three
colour carbon) from both methods. It is preferable to do some kind of
interpos/neg, while it's a question of doing as little harm as possible to
the originals as well as getting duplicates on modern material which is more
comfortable to work further from. Some of the technical photographic problems
are the low transparency, the spectral profile and the contrast. What is a
good interpos/neg? As usual it's depending on what you have in mind as a
final result, i.e. photographic colour print or duratrans, offset printing,
carbon printing or slides for slide shows. Our aim is to get dupes that suits
making separation negatives for colour carbon. Some ways to get useful dupes
are: to experiment with a) overexposure/underdevelopment and colour filter,
b) fogging the film, either a neutral fogging or a slight coloured one. The
amount and way of fogging is depending on the original, the next step in the
process and the kind of film you are using. Fogging is a little critical,
make sure that you use a lab that has very good control of their E6 process.
After the fogging make a filtered main exposure. Of course the computer and a
software like Photoshop are very good tools to solve the colour
sensitometrical problems, but first when your equipment is properly
calibrated to your film recorder, but that is another story....
A very good text about autochromes is written by Bertrand Lavedrine in "Les
Documents Graphiques et Photographiques, Analyse et Conservation 1991-1993"
ISBN: 2-11-003007-0. This text, as well many others, covers only the plates
manufactured by Lumiere. Is someone knowing if there are some literature
about all the other manufacturers. Gert Koshofer has written very good about
the other dot/line screen plate manufacturers in his "Farbfotografie", but
sometimes you want to know a little more.
Hans Nohlberg & Chia N-Lofqvist
email: Hans Nohlberg@online.idg.se