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MDR
11-30-2011, 09:58 AM
Just visited a friend in a film archive and was looking at snippets of some of those beautiful pre war emulsion like Kodak Super Sensitive Panachromatic and the like and I was wondering if it's possible to coat prewar thick emulsion with the new Kodak, Agfa, Ilford coating machines ?
I am grateful for any answers.

Dominik

BrianShaw
11-30-2011, 10:02 AM
I don't know the answer; there are people here that I think will know, though.

That is a fantasy of mine too!

dwross
12-01-2011, 10:50 AM
I can't imagine why not. I think the issue is at the kettle end of the process, not coating. A company needs to believe there's a market for the old beauties, and then it will happen. I actually kinda think it's going to go in that direction. Just as Ilford now does custom format cutting, someone will (and of course, this is my conjecture/hope only) make custom runs of emulsions. Lodima is a brilliant example of what can be accomplished with enough love and effort. Fingers crossed. More people need to have Dominik's experience of looking at the real deal to realize -- all over again -- the potential of silver halide photography.

Diapositivo
12-01-2011, 02:09 PM
I suppose in certain cases old emulsions cannot be recreated because they employed toxic substances which are now outlawed or which in any case the film maker would not want to employ to avoid bad publicity. In other cases maybe it's the developer which is toxic. I suppose this applies mainly to colour material. Certainly somebody else can make a more informed observation on this matter.

railwayman3
12-01-2011, 02:49 PM
My understanding, from the Ilford/Harman factory tour, (and apologies if I'm pre-empting anything Simon might post) was that their largest machine can coat not only all the different film emulsions but also paper. So presumably, and theoretically if not economically, it could be done?

Steve Smith
12-01-2011, 02:57 PM
It's also possible that these older thick emulsions were coated in more than one pass.


Steve.

Photo Engineer
12-01-2011, 03:00 PM
The old emulsions can not only be coated on modern equipment, they can be made on modern equipment. In fact, some of this emulsions are being made and coated on the original 1920s - 40s equipment. This is being done by some of the Eastern European companies.

Many of these were Ammonia digest makes such as found in the FIAT or BIOS reports. The best book description is in Baker (2nd Edition). It is the basis for my own film / plate emulsion.

PE

MDR
12-01-2011, 03:38 PM
Thank you for all the replies

Dominik

kb3lms
12-01-2011, 04:07 PM
It would be really nice to see someone make some of these older formulas. Probably on a one or two short runs per year basis. Maybe if the R&D doesn't really have to be re-created it might even be economical for the manufacturer but I would not expect the film to be cheap to the consumer as it would be a low quantity "custom" product.

Is there anything currently available in 35mm that would be classified as an old-style emulsion? I would like to try one.

MDR
12-01-2011, 04:38 PM
I believe Efke/Adox is the oldest Emulsion in production but has nothing in common with pre-war emulsions, as it was the first of the new thin layer(s) emulsions. Forte was to my knowledge the last company to produce thick layer films (Fortepan) :(
Maybe that filmcoating company in Iran or Tasma in Russia still produce old style films?

Dominik

Photo Engineer
12-01-2011, 05:33 PM
A custom run, with today's prices of raw materials and the development needed to insure that the emulsion and coating will work as intended will run between $50,000 to $100,000 US. This is just OTOMH. It will probably require about 6 to 18 months from a standing start to make it.

PE

dwross
12-01-2011, 05:52 PM
I suppose this is a good time to point out that we don't have to be dependent on factories to produce old-style emulsion film. An exact duplication of a specific old film might be hard-to-impossible -- even for factories (lost secrets and ingredients), and sprocketed 35mm will certainly be a diy challenge, but many of the sumptuous characteristics of old emulsions can be re-created in the home darkroom. I just made a dozen 120 rolls for less than $10 in materials. I do have a darkroom and a couple of pieces of lab equipment, but the equipment cost came in at less money than my Pentax K7 set me back and I predict that silver nitrate will always cost less than Epson ink cartridges :blink:.

wildbillbugman
12-01-2011, 05:57 PM
OK,I'm in! Who else wants to go in on a $100,000 run? Which old emulsion should we go for? I am willing to sell my old press camera to pay for my portion.
People were longing for the "Old Emulsions" back when I took Photo 101 and digital cameras were just starting to come out.
Bill

Crashbox
12-01-2011, 08:20 PM
If I had the disposable income to do so, I would jump in head-first!

Panatomic-X (I pretty much gave up photography the first time when EK DC'd it), Verichrome (pre-1956)... I'm drooling already...

wildbillbugman
12-01-2011, 09:13 PM
P.E.,
When we are talking about commercial "thick film" from the Good Old Days, just how thick are we talking about. If you can, I would like to know, wet as well as dry thicknesses. When people speak of the old "silver rich" films are they correct? Did these films contain a higher leval of silver than "modern films"? I have been told that they did not.
For" thick" film film, was something added to speed up or, even permit, absorbing of pre-wet and developer?
Like maybe starch?
Bill

Photo Engineer
12-01-2011, 11:05 PM
Bill;

Silver rich has been described by me over and over here. Basically, early emulsions had a lot of "dead" grains. Grains of Silver which would not expose properly or develop properly! It therefore took a lot of silver in excess to get to a "normal" Dmax by today's standards.

This was in excess of 300 mg / ft square for film and in excess of 100 mg / ft square for paper. (Approximate OTOMH).

So, Silver rich was a name for "faulty emulsions" IMHO. Today, my own Azo type emulsion and others I read of here are using more silver than they need if they are properly sensitized.

Thick also refers to gelatin. Today, we can use ISO wash or UF wash to concentrate an emulsion. 50 years ago, emulsions were diluted by washing.

So, there are 2 factors in operation here!

PE

MDR
12-02-2011, 07:07 AM
50 000 to 100 000 sounds reasonable I thought it would be more expensive unfortunately I don't have that kind of money lying around :(
Dwross I agree with you,my question was a purely academic one. Btw I am about to try out Kevin Klein's emulsion from your Website thank you for that great ressource (the lightfarm).

Dominik

dwross
12-02-2011, 11:34 AM
Excellent, Dominik! I hope you have great luck and fun (Actually, I'm quite sure you'll have both.) Feel very, very free to contact me if you have questions or comments along the way. I don't know if you've seen this (http://www.thelightfarm.com/cgi-bin/htmlgen.py?content=03Nov2011) because I haven't gotten around to making a bunch of links between old info and new. I'd love to hear how it works with Kevin's emulsion. I haven't personally tried that yet.
d