Hmmm......... He also said this in a comparison of BPF 200 and JandC classic 200
Yesterday I ran a set of BTZS type tests of some J&C Classic 200 film. Five step wedges were given identical exposures, timed with a Metrolux light integrator, and each one was then developed for a different amount of time in a 22:100 dilution of Pyrocat-HD, in BTZS type tubes using constant agitation in a water-bath. I subsequently read the negative densities through the Visual, Blue and UV channels of my densitometer, and finished by plotting the curves with WinPlotter.
Consensus opinion on this list and in other forums seems to be that the J&C Classic 200 film is same as Bergger BPF. For that reason I based my exposure and development times on previous tests of BPF film, which turned out to be too long to provide me with as much information as I like to get from this type of testing. However, a comparison of the results from testing of the two films showed some interesting differences. I donít have any idea who really makes these two films, but if they are made by the same company there are some substantial quality control issues involved.
BPF 200 and J&C Classic 200 are similar in that both are thick emulsion films that respond well to Pyro developers. And both give off in the pre-soak water the same blue/green dye from the anti-halation layer. But that is about it for the similarities.
The fundamental differences I observe from the tests are.
1) J&C Classic 200 develops to a given CI much faster than BPF200. For development to a density range of 1.60 (UV reading) for a SBR of 7, BPF 200 needed about 9 minutes of development at 70F, J&C Classic only 4:30 minutes.
2) J&C has a higher effective film speed than BPF 200. With development of J&C film for alternative processes I would recommend using the recommended film speed of 200 for use in the field. By contrast, BPF 200 needs to be rated at about EI 100, even when processing to a high CI, and even lower if developing for silver gelatin printing..
3) J&C 200 will develop to a higher maximum CI than BPF 200. With Pyrocat-HD used at the 2:2:100 dilution at 70F I was able to get a maximum gradient of about 0.95 with 9 minutes of development with J&C Classic 200. By contrast, BPF reached a maximum gradient of only about 0.80 at 20 minutes of development. This suggests that J&C Classic 200 would be a much better film than BPF 200 for use in low contrast scenes, especially with negatives meant for alternative printing.
For dual purpose negatives such as AZO and PT./PD, or AZO and Carbon, or AZO and Kallitype, Pyrocat-HD and J&C Classic 200 are a very nice combination. A negative developed to a DR of about 1.3 for AZO will have a much higher effective DR with alternative processes that use UV light because of the increased filtration of this light by the stain, so it would work well for a process such as palladium that has a paper ES of about 1.75."
two different thoughts.