Classic 400/Arista.EDU 400
By all accounts the current versions of FortePan 400, ClassicPan 400, J&C Classic 400, and Arista.EDU 400 are made in the Forte factory in Hungary, and should be the same film. But I recently tested film from one batch of J&C Classic 400 0321714, exp. 09/2005, and one batch on Arista.EDU 400 0322552 exp. 11/2005, and the Classic 400 was noticably faster (maybe 1/2 stop) than the Arista.EDU, though both produced printable negs.
I've attached an unmanipulated scan of the two 5x7" negs scanned in one sweep on my Agfa Duoscan. The top is the Arista.EDU and the bottom is J&C Classic. With some curve adjustment (not applied in the attached scan), I could get similar results from either neg, and the sky has good detail on the neg that could be burned in on a real print. The Arista looks better in the full 1000 ppi scan, but don't presume it's a better neg, because the denser J&C neg will likely print better on Azo (I haven't printed them yet). The purpose of the test is not to determine which film is better, but whether they are the same or not.
Since this was an outdoor scene with the possibility that the light could change from one exposure to the next, I took one with J&C Classic, one with Arista.EDU, and a third with J&C Classic and picked the two that seemed closest, though the two J&C Classic negs were quite similar. They were tray processed in the same batch.
I am inclined to believe that these are made in the same factory and are probably intended to be the same film. The base, packaging, and serial number sequence are the same. Classic has one generic notch, and Arista has three notches. If this is the standard of consistency, however, it might be a good idea to buy the film in larger batches and test each emulsion batch as if it were a new film.
5x7" Press Graflex
12"/6.8 Gold Dot Dagor at f:22, 1/40 sec.
2 min presoak
ABC pyro 1+1+1+7, 68 deg. F., 12 min, tray processed with constant agitation
30 sec. water rinse
3 min TF-4
15 min wash
1 min agfa Sistan
David, could it be that the factory makes slight changes in formulation so that each name product is not exactly the same? I don't know anything about film manufacturing but it seems these differences are persistant, although I cannot determine if they are consistent.
It might be, but I don't get the sense the differences are intentional or regular. John from J&C has stated that he's been to the factory, and confirmed that these various brands are cut from the same master rolls.
Maybe Jandc can tell us if we could order large amounts of a given film and be able to request the same batch number (I'm talking like 1000 sheets or so). I'd hate to re-test for every batch number. This sounds like going back to the '60's technologically. I know at some point batch runs became consistent enough that I could not worry about it. If I want to standardize on EFKE 100 for instance, do I really need to order a lot of film from the same batch to get consistent results?
The Forte 400 film is a very old emulsion receipe. While Forte modified it recently to get better speed and density it is still based on this old formulation. One of the drawbacks to this is the stability of the emulsion. Forte will not date this film for greater than 2 years from manufacture. Even over the course of the 2 year life span stored at room temperature the film will change significantly. We have always bought Forte films in small frequent batches for this reason. This is also the reason we are out of stock on so many of these films right now as Forte trys to get back into production. We have also invested in an underground climate controlled cool room to store all of our film stocks. We also always ship our films from both Europe and China by air freight instead of the cheaper surface methods available to minimize the time the film is uncontrolled.
Originally Posted by mikewhi
For these reasons I suspect the reason you are seeing differences is not due to significant production differences in the film but rather to aging differences.
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This seems to coincide with some tests Sandy ran a while back. He found that the Classic 200 (if I'm not mistaken) was the same film as others, but thought that batch to batch variations were to blame. Age would make a difference, perhaps more than batch variations. I'm wondering, how will this film hold up with respect to age in cold storage? It doesn't sound as if it would pay to stock up on huge quantities unless it is stable.
If the expiration date of the two batches is two months apart, how much could the age difference be, and why should the older film be faster than the fresher film?
Ultimately, I guess the question will be whether it is better to buy in small batches more frequently, so that the film is as fresh as possible, or to buy in larger quantities less frequently so that the film will all be from the same batch.
We have seen in the past a half stop or more of speed reduction in this film over the course of a year for film left at room temperature (70-80) versus 50-55 degrees. So it is possible that older film stored at optimal conditions would be better than newer film stored under average conditions.
Originally Posted by David A. Goldfarb
Thanks for the info, John.
While I realize that the test isn't that precise, I'm fairly confident that two batches of Tri-X made in the same year are going to be closer, since I've often been in situations where I've used Tri-X from two different batches, and that consistency means I can get good enough results by eyeballing the negs and examining prints without testing each batch. If batch to batch consistency and age are a larger factor for Forte/Classic/EDU 400, though, there's more incentive to replace my old densitometer (the one that died a few years ago) and test more frequently and more carefully.
It has been a couple of months since this discussion took place, but I was wondering if anyone had any further insight on J&C400 and the effects of time.
I am looking for a film to standardize on and because of cost and film speed I looked toward this film initially, but if there are going to be big problems....
Just as a note, I do cold store my film in a mini-fridge, but it has recently been moved into a freezer. Any opinions on J&C400/Arista.edu400 over time?
Let's see what I've got in the magic trash can for Mateo!