Forte 400 Film- Times

[braxus]

I have a few rolls of the 400 in 35mm. Its dated March 2002. First off should I rate it at 200 ISO or even lower? Secondly if I develop this myself in Xtol straight mix, can you recommend a developing time for this? Or should I wait until I get some HC 110 developer first? If I use that, what dilution and time would you recommend for that? I dont know the history of how the film was stored most of its life, as I got it a couple years ago off Ebay. I have 2 more rolls of this film too. So this will be a test roll.

The MDC site says 12 minutes for Xtol straight, and 9 minutes for Dilution B in HC 110. This is at 400 speed however. In HC110 its stated to be 7 1/2 minutes for 200 speed for HC110. Im not sure the stock time of 12 minutes for Xtol straight is correct, as D76 is only 9 minutes.

 

[Lachlan Young]

I used some Forte/ Classic Pan 400, expiry 2008 or thereabouts, in the early 2010's & processed in Xtol. It wasn't particularly low in base+fog levels. Didn't notice much of a speed loss. Expired film often needs longer process times, which need to be balanced off against fog generated by longer processing times. Personally, I'd tend towards something fairly fast acting & very low fog - Rodinal or PQ Universal.

 

[braxus]

Well this film is 18 years expired and I cannot confirm how it was stored most of that time. Should I just shoot it at box speed and develop normally just to see how it turns out?

 

[Donald Qualls]

You said you have several rolls? Shoot one with bracketing -- frames at box speed, 1 stop slower, 2 stops slower, 3 stops slower -- and then process normally. You should find what you need in that range. If you find that all the negatives are low contrast (due to high fog?) you can adjust developing time, but you'll already know what exposure looked best.

 

[braxus]

Thanks Donald. That is helpful. I'll do that.

Actually I only have 3 rolls in total. But Im trying to see if I can buy some more (with different date of course).

 

[braxus]

Donald. Does the 12 minute time for Xtol straight sound right to you? Reason I ask is on the same information section, they list Xtol 1:1 at 12 1/2 minutes which isn't much longer then the straight time. And D76 says 9 minutes.

 

[Donald Qualls]

I've only done one tank of 15+ year old Forte 400 in 4x5 recently -- and I recall using the MDC time and getting negatives that were okay for contrast (they had other problems due to being in the film holders for more than 12 years, but seemed correctly developed). I've just done a fast search, and found 8:30 at 24C and 7:30 at 20C -- suggesting notbody ever really knew.

That said, part of this might be people trying to compensate for a widely held belief that Forte 400 was actually a 200 speed film (same thing they say about Fomapan).

 

[braxus]

Well I opened up my box of Forte 400 and this paper slip was inside. This might prove helpful for others down the line too. You were correct. Forte even said this film is better at 200.

 

[Lachlan Young]

Forte even said this film is better at 200.

That note is for Microdol-X/ Perceptol type developers which lose about 1 stop of speed when used at stock strength and ISO contrast (CI of 0.6). You can develop to a higher contrast and try a higher EI, which may or may not deliver adequate shadow detail for your taste.

 

[MattKing]

That note is for Microdol-X/ Perceptol type developers which lose about 1 stop of speed when used at stock strength and ISO contrast (CI of 0.6). You can develop to a higher contrast and try a higher EI, which may or may not deliver adequate shadow detail for your taste.

I think you may have missed the first part of the notes, which indicate that the 400 speed is for artificial light, and recommends an extra stop of exposure for daylight.
The daylight speed for Microdol X would be 100.

 

[Lachlan Young]

I think you may have missed the first part of the notes, which indicate that the 400 speed is for artificial light, and recommends an extra stop of exposure for daylight.
The daylight speed for Microdol X would be 100.

I can't say I encountered that with the film I used - normally it would go the other way, with 1/3 stop loss under tungsten - albeit, I tend to give fairly generous exposure to BW film anyway. While the Fortepan does claim extended red sensitivity, this sheet essentially suggests that the blue/ green sensitivity of the film is severely suppressed. I wonder if something got lost in translation, because otherwise you'd have a very noticeable gap in tonality. I do recall seeing a spectral plot for the Forte films, but can't remember where - I don't think there was a major green gap.

Edit: Have had a fairly slow & painful dig through the archived Forte webpage & also found the ClassicPan 400 datasheet too. Neither suggest adding a stop in daylight. Have attached the ClassicPan data sheet for the 400 - there are some interesting transcription/ OCR scan errors which make it a little challenging to read. Note: there was a change in the ClassicPan 200 to a 'New' version, with changed development times. In terms of the rising sensitivity from blue to red (presumably exposed under a tungsten source), the pattern roughly mimics that of Foma's films - obviously it won't match as they have/ had different makes, sensitising dyes etc. It may well be that like Fomapan 400, ClassicPan 400 needed a speed boosting PQ/ PA developer (Microphen/ Xtol) to get within 1/3 stop of officially rated box speed. Note that Fortepan's 'box speed' is at a gamma of 0.8 - most would consider that a fairly hefty push, given that 'normal' is closer to 0.65 gamma. This may be a legacy of optical systems with higher flare levels being in more widespread use in central/ eastern Europe to a later date than in the west. Development to a more 'normal' gamma (as it would be understood by most users of modern films) would probably benefit from a stop of extra exposure.

 

[Lachlan Young]

Where do I find this archived Forte webpage?

It can be found on archive.org - what are you trying to find out?

 

[eatfrog]

First I would like to find the archived pages on archive.org, but cant find it. Do you have a direct link?

https://web.archive.org/web/20070809093245/http://www.forte-photo.net/indexe.htm

 

[Paul Howell]

If it were me I would shoot at ISO 100 then develop in Divided D76, 5 minutes part A, then 5 in part B, water rinse, then fix and wash. If you have trouble ordering from PF here is the formula.

Solution A Kit size Chemical 1 liter 2 liter 4 liter Distilled water (52° C/125° F) 750 ml 1500 ml 3000 ml Metol 4 g 8 g 16 g Sodium Sulfite 100 g 200 g 400 g Hydroquinone 7.5 g 15 g 30 g Potassium Bromide, 1% 30 ml 60 ml 120 ml Cold water to make 1000 ml 2000 ml 4000 ml To prepare Solution A, place the warm water in a mixing bowl and add a pinch of sodium sulfite. This small amount of sulfite minimizes the initial oxidation of the metol; however, if more is added at this point, the metol will not dissolve. Add the metol and stir the solution until dissolved. It is important that all of the metol is dissolved before proceeding. Then add the sulfite and, again stir until the solid has dissolved. Next add the hydroquinone and stir until dissolved. Measure the proper volume of the potassium bromide solution and add it. It is important that only the specified amount of the 1% solution be added. (Do not add all of the solution that was mixed!) Finally, add water to bring the total volume up to 1 liter (2 liters, 4 liters), stir to ensure it is homogeneous, and then transfer the final mixture to its storage container. Solution B Kit Size Chemical 1 liter 2 liter 4 liter Distilled water (52° C/125° F) 750 ml 1500 ml 3000 ml Borax 60 g 120 g 240 g Cold water to make 1000 ml 2000 ml 4000 ml A