Discussion in 'B&W: Film, Paper, Chemistry' started by NER, Aug 1, 2004.
Does anyone here happen to know what Bergger claims the resolving power of this film to be? Thanks.
That will depend on a variety of things in addition to the film's characteristics. Among those will be the taking lens and the developer used.
I've heard 80 - 85 lp/mm, but I haven't tested it myself.
Classic 200 listed at 80 lines/mm, Classic 400 at 70 lines/mm. These values are typical of what can be expected from traditional emulsions of similar speeds. I expect Bergger is about the same. Keep in mind that these are maximum with high contrast test targets and optimal development. Lens quality, stability of camera, subject contrast, etc all come into play.
Bergger is a genetic twin of Classic 200 so I would expect the resolving power of the films to be very similar
Thanks. I know what resolving power is. I was looking for a lpmm number. I have posed this question to Bergger. If they write back, I'll let you know what they say.
I doubt that any manufacturer will commit to a lpmm number without a lot of qualifications. Usually I have seen resolution numbers posted by a retailer or other third party.
Maybe. But here (http://www.efkefilm.com/Efkedata.htm) Efke publishes 90 lines/mm for PL 100.
The same as Classic 200, 80 lpmm as quoted by the manufacturer.
Can you direct me to the source (a URL, perhaps) of this information, please? Thanks.
Forte 200 is the same film as Classic and Bergger.
I was under the impression that Bergger Products, Inc. and Forte Photochemical Co. Ltd were separate and unrelated business concerns with no corporate relationship. I believe, but do not know for a fact, that "Classic" is made by either Fotokemika d.d.(Croatia) or Adox Fotowerke, Inc. (Canada). Can you clear this up for me? Here is the Forte link in English: http://www.forte-photo.net/e/sf200.htm
It seems that Bergger has it's paper made by Forte following Bergger formulas. The films simply appear to be the same. At least packaging and notch code are. I'm about to test these seemingly different emulsions to see what's the truth.
NER: J&C is the distributor for the Classic films in the U.S., so that info is from the source. I've corresponded with Mirko at fotoimpex, which is the European distributor, and he has also confirmed that the ClassicPan (the European version) films are manufactured by Forte, and not Efke or Adox. To further confuse matters, while Classic/ClassicPan 200 may be the same as Fortepan 200, New Classic/ClassicPan 400 is not the same as Fortepan 400, though Forte makes both of them.
The source said 80 lines/mm, however, Forte claims that the resolving power of its film is 85 lines/mm: a discprepancy of 5 lines/mm is not one I am likely to see with or without glasses and I am not concerned by the small difference. Maybe I'm approaching my problem from the wrong direction. Let me explain why I posed this question in the first place. I ventured down this path because I am considering a switch to Efke PL 100, which is said by its manufacturer to have a resolving power of 90 lines/mm. I like BPF 200 for several reasons, but despite using it for some time, do not know its resolution rating. Comparing the resolving power of the two emulsions and evaluating my results from BPF 200 would, I reasoned, give me one indication of what to expect from PL 100 and would be a more objective and reliable indicator than looking at the results obtained from PL 100 by other photographers and posted on the internet, some of which are very impressive. My interest in completing this evaluation would not be as high were not for the fact that PL 100 is considerably more expensive than BPF 200. 25 sheets of 8x10 BPF 200 is $60 at Bostick & Sullivan, while 25 sheets of PL 100 is $109.99 at JandCPhoto. That's my story. Bergger has not yet responded to my inquiry.
[I stand corrected on the price charged by JandCPhoto (see below). JandC's price is for 50 sheets, not 25.]
no longer hijacking this thread
Because I may like it more than BPF 200.
I think it would be very difficult to tell the difference between 80 and 90 lines per mm.in the negative. Paper can resolve only 30 or so lines per mm and unless you are examining your enlargements with a loupe I do not understand your concern.
while 25 sheets of PL 100 is $109.99 at JandCPhoto.
I think you need to check the JandC Photography website again. Looking at the website, tells me that the Efke is packaged as a 50 sheet box. There by making it about $54.99 per 25. That compares favorably to the BPF 200 from the Bostick and Sullivan company.
I have no interest in JandC Photography other than wanting to see the company succeed.
Andre - I've stated my question and the reasons behind it. If you have something more constructive to say, I'd like to hear it. If not, please go hijack some other thread. Thanks.
You're right. 50 sheets/box. My mistake.
I have no idea what you're talking about. According to John Carroll (Photographic Facts and Formulas, Prentice-Hall/Amphoto 1976), the human eye is thought to be capable of resolving 1/100 inch at normal reading distance, i.e., about 0.254 mm. I just want to know the resolving power of BPF 200.
So, if a paper can only resolve 30 lp/mm paper, and your film can only do 90 lp/mm you can only enlarge your negative three times before the image becomes blurred. For a 35 mm negative that would mean a 7,5 x 10,5 cm (3x4 inch) print. Don't you think that's a little bit small? ;-)
I can see that this thread has become a little tense and what I have to say is not intended to annoy you, just to approach it from a different angle...
What are your reasons from considering moving to PL100 from a film which you like and presumably know well? Finer grain?
If you are shooting 8x10, the LPMM issue is all but irrelevant in that both are traditional films and will be a million miles away from TMAX 100 or acros and probably quite similar to each other in terms of LPMM/resolving power. Between the films listed the resolution issue is unlikely to become significant below 30 or 40 inch prints if at all.... The 'look' will be much more important and the tonal characteristics and curve may be very different. A good example would be Acros and Tmax100, which on paper are very similar (curves, grain etc) but on a print I think are very different. If you use PL100 (A truly beautiful film) you can always bend it a little by selecting a different dev to the one you are using now. All I am saying is that the Lpmm will tel you little to nothing about its photographic potential for YOU. Use it, develop it, experiment a bit and print it, then decide! I bought quite a lot of TMAx 100 readyload before I realised that I did not like the look of it on paper! I thought all the folk who said they did not like the look of it to have a touch of emperors clothes about them. Not so. I f you like traditional films, you will like PL100. Good luck, Tom
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