Van Dyke / Cyno - Idea w/ Enlarger

[dodphotography]

Hey everyone, I got to thinking and was curious if someone could help me or simply tell me I'm wrong.

If we coat some paper with the appropriate chemistry... what is to stop you from enlarging a negative onto the paper if your head was fitted with a UV bulb? Or, are UV bulbs not available for enlargers?

Why must these always be contact printed?

Thanks,
Dan

 

[cliveh]

I think there has already been a thread or two on this and the outcome was it wont work (not enough UV output).

 

[Hexavalent]

"Regular" optics do not fare well with UV, specialty ($$$) glass is required. As VDB, cyanotype, etc., are very slow processes compared to silver-gelatin, exposure times are very long. The Fresson lab in France does use an enlarged negative system, but exposures take hours even with an arc lamp, and the negatives get rather cooked in the process.

 

[Bob Carnie]

I have only seen one Fresson Print by Shelia Metzner (sp)

Can you direct me to artists that use this process regularly or where I can see a collection of these prints.

thanks

Bob

"Regular" optics do not fare well with UV, specialty ($$$) glass is required. As VDB, cyanotype, etc., are very slow processes compared to silver-gelatin, exposure times are very long. The Fresson lab in France does use an enlarged negative system, but exposures take hours even with an arc lamp, and the negatives get rather cooked in the process.

 

[MDR]

Luis Nadeau operates a Fresson Lab in Canada

Luis Nadeau
P.O. Box 221 Station A
Fredericton NB
Canada E3B 4Y9

Scott Macleay works in the Fresson Process another Canadian
www.scottmacleay.com

 

[Bob Carnie]

Not so sure Mr Nadeau is actually making prints, I have a couple of his books which are quite good, but if he is printing, he is not showing .

I will look into Scott Macleay work

thankyou.

Luis Nadeau operates a Fresson Lab in Canada

Luis Nadeau
P.O. Box 221 Station A
Fredericton NB
Canada E3B 4Y9

Scott Macleay works in the Fresson Process another Canadian
www.scottmacleay.com

 

[Hexavalent]

AFAIK, Luis hasn't been making Fresson prints for quite a while, focusing rather on conservation work. He used large negatives for exposure, rather than a UV enlarger.

 

[Bob Carnie]

thanks I thought so what does AFAIK mean , I am over 60 and slow now

 

[MDR]

Bob since you are canadian you probably had some french in school so you can probably contact the Fresson family and get some informations regarding the homemade enlarger it seems they used this method only for the mono fresson process and not the four colour process which requires separations negatives. They used an arc lamp for cinematic projectors as UV source and built the enlarger around it. Note: Rodenstock made a UV enlarger lens the UV-Rodagon.
email: fresson@atelier-fresson.com

 

[MDR]

Just found that Pentacon build and sold and UV enlarger in the 1960's it was called the Pentacon Multifoc UV. a bit more info: http://books.google.at/books?id=NrE...a=X&ei=6WvQUtTSEYaO7Aaa84CYBQ&ved=0CFMQ6AEwBQ
and an article in german http://www.gigabitfilm.de/download/uv_projektor.pdf

 

[Bob Carnie]

I speak only English

I am more interested in seeing a few prints, I have no interest in learning the process, I already have too much on my plate in relationship to four colour pigment prints.
Lately I have been turned onto the intaglio process with pure pigmented inks and am following this by making registered direct to plate so that I can make some prints on a Conrad Press.


QUOTE=MDR;1594858]Bob since you are canadian you probably had some french in school so you can probably contact the Fresson family and get some informations regarding the homemade enlarger it seems they used this method only for the mono fresson process and not the four colour process which requires separations negatives. They used an arc lamp for cinematic projectors as UV source and built the enlarger around it. Note: Rodenstock made a UV enlarger lens the UV-Rodagon.
email: fresson@atelier-fresson.com[/QUOTE]

 

[MDR]

Even though he no longer practices the process Luis Nadeau has some to view the best known artists working with the process were/are Sheila Metzner and Sara Moon. Not so many photographers working with this process especially outside of France. Furthermore the Fresson family did not accept commisions by just everyone only a few selected artists they deemed worthy of the process were accepted as customers, this is no longer the case.

 

[Hexavalent]

AFAIK = As Far As I Know

thanks I thought so what does AFAIK mean , I am over 60 and slow now

 

[Gerald C Koch]

It would be much easier to make a copy negative of the appropriate size and use this to make a contact print.

 

[MDR]

Why would it be easier more steps are necessary to make a copy negative than a direct enlargment. Also looking at the Pentacon example which was designed for chloride emulsions that were only sensitized for UV-light the exposure times using a 50w mercury vapour lamp as lightsource were not that long.

 

[jp498]

Cyanotypes are magnitudes slower than contact printing paper. You'd likely warp or melt the negative with the amount of power needed to enlarge it onto cyanotype. Copy negative or digital negative are the way to make bigger cyanotypes from smaller film.

 

[cliveh]

Why would it be easier more steps are necessary to make a copy negative than a direct enlargment. Also looking at the Pentacon example which was designed for chloride emulsions that were only sensitized for UV-light the exposure times using a 50w mercury vapour lamp as lightsource were not that long.

What do you mean by not that long?

 

[MDR]

According to the linked source (german one in my previous post) around 30 to 50 seconds for Agfa Lupex lens at f4.5 x9 enlargment

 

[cliveh]

According to the linked source (german one in my previous post) around 30 to 50 seconds for Agfa Lupex lens at f4.5 x9 enlargment

I find that very difficult to believe, did he mean 30 hours?

 

[MDR]

Nope seconds the article also states that the exposure time varies according to the film different films have a different amount of UV transmission. They also advise to either get an old (old as in already old in the 1960's) CZJ 4.5/50mm Tessar or an Emil Busch Orthan 4.5/55mm lens as the coating of modern lenses absorbs too much UV light and these two older lenses focus visible and UV light nearly in the same plane. As a personal note the pentacon/perner enlarger focused the UV light while 99% of all UV light sources for Alt.Process uses unfocused (diffused) light that loses a lot of it's energy.

 

[Gerald C Koch]

Why would it be easier more steps are necessary to make a copy negative than a direct enlargment. Also looking at the Pentacon example which was designed for chloride emulsions that were only sensitized for UV-light the exposure times using a 50w mercury vapour lamp as lightsource were not that long.

Because the two processes mentioned in the OP are so very slow and by slow we are talking about exposure times for cyanotype prints of from several minutes to several hours. Trying to get that much UV light thru the small aperture of an enlarging lens would take a very long time. This is also in addition to the fact that most glass formulations do not pass much UV light. UV spectrophotometers use cuvettes (special liquid containers) made of fused silica instead of glass. Remember too that UV light degrades most plastics including those used for film base. So one needs to limit the exposure time. If a copy negative is lost it is only an inconvenience not the loss of a precious image.

Any silver halide emulsion is orders of magnitude faster than the two processes mentioned. BTW emulsions do not have to be sensitized to UV light which is in their normal sensitivity.

 

[MattKing]

Todd Gangler moved into his carbon printing work as a result of working with the Fresson lab on an early project.

 

[Bob Carnie]

learn something every day thanks

AFAIK = As Far As I Know