"200ISO, but I wouldn't use it past 125" What does this mean?

aldevo · Aug 15, 2009

pentaxuser said:
I think this is a reference to the belief held by a number of photographers that unless this is developed in a speed increasing developer it really is a ISO125 film and Foma have used some licence in declaring it a ISO 200 film.

I can't speak from experience as I have never used it

pentaxuser

Probably not much license, actually. The ISO standard is based on a speedpoint (density 0.1 above base + fog, developed to a total negative contrast of 0.8 over an SBR of relative log 1.3) that tends to flatter box speed. It doesn't necessarily reflect likely exposure and development under true "battllefield" conditions.

Except for flat lighting conditions I think the statement for Fomapan 200 is true of just about every film I've tried.

ic-racer · Aug 15, 2009

If its anything like the Arista 100 and Arista 400 I recently tested, I wouldn't go past 80.
(there was a url link here which no longer exists)

Chazzy · Aug 15, 2009

The point about Foma 200's true speed being lower than 200 seems settled. May I ask what people like about this film? Is it only the price or does it have other redeeming virtues?

ic-racer · Aug 15, 2009

Chazzy said:
The point about Foma 200's true speed being lower than 200 seems settled. May I ask what people like about this film? Is it only the price or does it have other redeeming virtues?

Perhaps a little off topic, but the Arista 100 8x10 sheet film's backing is totally cleared when processed in the Jobo 2800 print drums. That is, no lines are left on the film from the ridges in the tank. Unlike, say FP4+, which under identical conditions, came out with faint lines on the film base at the points of contact with the ridges in the drum.

aldevo · Aug 15, 2009

Ian Grant said:
Not strictly true, the problem is that the ISO test for film speed can be done one of two ways.

The first is the old ASA/BS system, both identical for B&W films, which measures the films thresh-hold speed and the second is the German DIN standard which is very much more practical, somewhere back in the UK I have the full details of both test methods.

Kodak use the ASA method this is why bmany people downrate Tmax, Tri-X etc to get a full tonal range.

Agfa used the DIN system which is why their films almost always gave a true box speed. ISO speed includes ASA & DIN, in Agfa's case the 100/21° ISO of APX100 is just a conversion from the 21°DIN to 100ASA.

For all practical purposes I used to use Tmax100 @50 EI, and APX100 @100 same dev times etc and got virtually identical tonality etc.

Fomapan 200 & 100 need approx 2/3rds the dev times of all other films or they build up extreme conrast this will impact on the ASA testing done for film speed.

Ilford now quote EI's and dev times based on practical tests, so their approach is more akin to the DIN system.

If all manufacturers actually used the DIN method of testing there would be fewer anomolies, and Kodak Tmax100 would have been known as Tmax50 - ISO50/18°

Ian

I've never found APX100 or APX400 to give true box speed except in the same lighting conditions that Tri-X does. In fact, I generally rate APX 400 1/3 stop *slower* than Tri-X and I'm know I'm not the only one who does the same. APX400 is - at least in its post-2002 guise, no faster than Tri-X when you expose it at a scene with a high SBR.

Both the ASA and DIN standards pre-date the emergence of thin film emulsions. Unfortunately, assigning an arbitray speedpoint (e.g. 0.1 + b&F) as a standard representative of all thin film emulsions is questionable but that it just what ISO standard attempts to do.

Ian Grant · Aug 15, 2009

I no longer shoot 35mm Charles, but in 120 & 5x4 the results with Fomapan 200 (& 100) are superb once you nail the EI & dev times down for your own way of working.

Personally I still prefer Ilford (or Koda) films but sometimes Foma is all I can buy easily (10-20 rolls at a time) so it's worth my while being fully conversant with it as an alternative for when I'm short of Ilford films.

Ian

BradS · Aug 15, 2009

Chazzy said:
....May I ask what people like about this film? Is it only the price or does it have other redeeming virtues?

I bought and tried a whole box (50 sheets of 4x5) of the Fomapan 200. I resolutely do not like it at all. The film develops very fast and builds contrast so quickly that I found it very good at producing "Chalk and Soot"....and not much else. I'm glad I suffered through the whole box as it made me realize what fool's errand it is to try to save money on film. I have used nothing but HP5+, FP4+ and Tri-X ever since. Foma 200 convinced me that trying to save money on film is false economy.

Ian Grant · Aug 15, 2009

Brad, I've shot some exhibition prints with Fomapan 200 & 100 and you can't tell the difference between the Foma shots and the Ilford, but it does need taming. But once you get the EI & dev time sorted it's fine, some use the 200 at EI80

Ian

BradS · Aug 15, 2009

Yes, this is the beautiful thing about this universe of materials and processes. There is such a wide variety of good materials to work with - something for every purpose and person it seems.

I do not deny that Fomapan is a fine film in skilled hands. Far better, in my opinion, than Efke - and many folks coax beautiful results from that dreadful film as well. I am just not able to....that is all.

oskajan · Aug 27, 2009

Although my favourite film is HP5, it wasn't a long time ago that I put a roll of Foma 200 in my bulk loader to try it. I'm rating it mostly at 100 and develop it in ID-11 1:1 to get acceptable results.

A technical note: the claimed 110 linepaires/mm resolution of the film under high contrast conditions is correct, the last lines I could still separate on the negative of a resolution test chart were for 108 lp/mm. I rated it at 200 and developed it in Rodinal 1:25 for the test, the lens was an SMC Takumar 1.8/55 at optimum aperture. Contrast was extremely high, ligh was provided by a 1000W halogen lamp.

Aron

"200ISO, but I wouldn't use it past 125" What does this mean?

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