Sheetfilm from a no longer existend company called chemco.

Hi there,

For a while now ive been looking at this huge box of sheet film. I guess there's about 50 sheets of 40x50 ortho film in it. Its from this dutch company called Chemco. Formerly located near a dutch town called Soesterberg.

My dad received this box of film about 15 years ago when working for a photography initiative. It has been stored near room temperature ever since. Today ive cut a piece from a sheet just to make a test exposure. The results however where really disappointing. I could very faintly distinguish a picture of sorts. This was however already after 2 minute of exposure under my enlarger at about F/5.6.

Even when taking a piece of the film into daylight and developing it afterwards yield next to no increase in density. By comparing it to my stouffer stepwedge. I would say the fully developed and exposed film yields about a log. d of 0.10. Which is well, not usable at all.

Now i am wondering, might this be some sort of litho or printmaker film which requires a special sort of development? So far ive tried developing in paper developer(eukobrom) and in rodinal. The film is called Chemco HS P10 482. The film base seems to be colored yellow/amber, the unexposed emulsion looks a bit greenish. Below i will link to 2 images of the packaging.

http://imgur.com/3RVtjcV
http://imgur.com/GqHbFLk


I apologize for the poor image quality. The packaging is badly damaged so im a bit reluctant to bring it into a better lit room.

I would apreciate it alot if someone could identify this product, and tell me if im doing something wrong. Or if its more likely the film is just spoiled?

That link needs a Google+ account to open.

Pff. Everytime the same drama with google.

http://imgur.com/3RVtjcV
http://imgur.com/GqHbFLk

These should work atleast.

Rowan,

It can be many things , may be daylight prepress film , may be laser exposure prepress film ? I used hundreds of packages of 70x105 cms and even larger rolls for prepress printing press separations preperation. It was 20 years ago and packages were coming very similar to yours.

I dont know even the chemistry of these developers but we were using half a car size developing machines.

IMHO they are for ultraviolet blue laser exposure films and you can not use them for tonal exposures. They are totally useless , you can develop , collect the silver and sell. Even 20 years ago , these films were out of fashion. They required large rooms , large drums , expensive machines and developing tanks and criss crossing , running young operators.

Than AGFA made new machines , 1/100 size , small like fish tank and print at daylight in the same room of macs.

Owner banktrupted later.

That label does not make me wiser.

But I think of a direct-positive emulsion anyway.

Hmm Mustafa, AgX. Both your theories have merit. Would make sense for it to be direct positive as it would render an almost transparant negative when fully exposed. But as Mustafa says. It could be a uv paper of sorts. I will put a piece of it under my uv exposure box tonight, and see what happens. I dont got special developers or anything, so il just try it in rodinal.

Anyway thanks so far. And il let you know what i find out.

If you have any print developer handy, try that too - possibly at both normal and half strength. It is more active and therefore perhaps more similar to whatever speedy graphics developer was originally used with this material.

Martin.

Ive tried paper developer indeed. Eukobrom from ehm... Tetenal. Also ive used some rodinal at 1+25. The paper developer indeed gave a more prenounced result. But still far from usable.

Rodinal 1+7 for 3 minutes, leave it in sunlight for 5 minutes first.
In the past Rodinal was used for paper.

Look into Kodak PMT (Photo Mechanical Transfer) material for info on this. Your box is the Powers Chemco version of it. It s a direct positive process and uses a negative and a receiver sheet to make the usable image. It also uses a "activator" and not a developer. Also it is a "hard dot" style material, good for half toning and really bad for anything continuous tone, used to make printing plates. Much faster workflow then using film in the process camera back in the day. It used a diffusion transfer development method for processing. You need both sheets and the activator to use this "correctly".

Ingredient list (from the MSDS) for the Kodak activator:

1) Water
2) Sodium sulfite
3) Sodium thiosulfate
4) 2-Methylaminoethanol
5) Glycerol
6) Hydroquinone

Also a related photo in another thread from 2012:
(there was a url link here which no longer exists)