FomaPan 200 Reciprocity Question

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Ian-Barber

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Based on your previous testing, personal reciprocity charts and actual experience out in the field (not some information floating on the web), ,if you had a metered exposure of 12 seconds, what actual exposure would you give the film ?.
 
Ian-Barber said:
Based on your previous testing, personal reciprocity charts and actual experience out in the field (not some information floating on the web), ,if you had a metered exposure of 12 seconds, what actual exposure would you give the film ?.
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Two cups of coffee and a Mars bar at f45....:)
 
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Fomapan 200 tech data, 3 stops extra according to Foma. I did my own tests around 2007 and found it wasn't that much more like a stop at 10 seconds, but then I shoot the 200 at 100EI.

Ian
 
Ian Grant said:
Fomapan 200 tech data, 3 stops extra according to Foma. I did my own tests around 2007 and found it wasn't that much more like a stop at 10 seconds, but then I shoot the 200 at 100EI.

Ian
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Now this is interesting and here is my reason for asking....
Yesterday, I made an exposure on 5x4 FomaPan 200, the meter reading was 12 seconds.

Looking at the Reciprocity app on the phone which is data pulled from FomaPan datasheets, it indicated a correct exposure of an extra 3 stops.

I stood for a moment, pondered and smoked a bowl of bacca in me pipe.....
My gut feeling told me that the +3 stops from the App was not correct so I opted to increase the exposure by +1 stop and the negeative has developed really nice from toe to shoulder.

So, from your experience, does this +1 stop follow suite as we we move further up the scale
 
I only tested at 1 second and 10 seconds in very low light levels, it needed 1/3 of a stop at 1 second, and a stop at 10 seconds. I actually tested Fomapan 100 first, later the 200. As I said, I always shoot Foma films at half box speed, I would expect that at longer exposures like 100 seconds 3 stops extra would be needed.

My longest exposure was roughly 4-6 minutes inside a canal tunnel, the film was either Agfa APX100 at box speed or Tmax100 at 50EI. I never wear a watch, this was before mobile phones, so I had to count. I only gave an extra 2 stops exposure, it's an easy negative to print,

1751568689088.jpeg

Ian
 
I did some testing for myself and this what I came up with, curious to see if anyone else has ant data to share

fomapan 200.png
 
Great stuff. Would be very interested in your methodology.
 
I did quite a bit of research and I noticed perople was referring to the "Gainor Reciprocity" Formula so using the formula, I made this chart.

So far, I have tested it with my workflow to 20 seconds metered, 44 seconds adjusted with some decent results.

The Reciprocity Timer IOS App was giving me results which were not very good so I am not sure where they are pulling that data from

IMG_0577.PNG
 
Thanks for this Ian. When I was using Foma 200 I used a reciprocity failure chart that called for much more exposure than your chart. Can't remember where it came from but I'm sure it wasn't accurate. If a reading indicated 1 second, I gave it 2. If it indicated 2 seconds, I gave it 5. I never went beyond this. Perhaps it was a good thing I didn't because 15 sec on my chart translates to 2 minutes 40 seconds. On your chart 16 seconds becomes 32, i.e. one stop extra.
 
I have used Foma 200 in my 6x17 pinhole camera with very extended exposure times. The Foma films' exposure times seem to 'fall off a cliff', as I remember someone saying.

My guide exposure chart for Foma 400, which I prefer to use, contains these entries, a selection:

Fomapan 400, including reciprocity failure.

Pinhole f/233
Measured exposure at f22 and resulting time...
1/1000 1/8
1/30 19 seconds
1 second 15 minutes
and so on...
30 seconds 61 hours!
 
Ian-Barber said:
I did quite a bit of research and I noticed perople was referring to the "Gainor Reciprocity" Formula so using the formula, I made this chart.

So far, I have tested it with my workflow to 20 seconds metered, 44 seconds adjusted with some decent results.

The Reciprocity Timer IOS App was giving me results which were not very good so I am not sure where they are pulling that data from

View attachment 5428
Click to expand...
Hey Ian, I also was getting terrible results with foma 100,200 and 400 using this app. I found a data sheet on 100 which I found on the film and darkroom user forum and got consistent good results. https://www.film-and-darkroom-user.org.uk/forum/attachment.php?attachmentid=3421&d=1571901773

I couldn’t find one for foma 200 sadly. I’ve found that foma just isn’t good at reciprocity. I do motion shots and I decided just to use hp5 as the times after 1 second doesn’t become manageable when shooting talent. I would presume if you are shooting landscape it may not be an issue. When I get back I’ll have another dig. I decided foma would be for strobe work and really sunny days.

It’s been a while, hope everyone is doing well.
 
I've been using the Reciprocity+ app for iOS on my phone for years. It is generally reliable/accurate. But when I started using Fomapan 100 and 400 in sheet film sizes, I found the "official" reciprocity adjustment values the app gave me were way over the top once I was starting with anything longer than about 3 seconds.
For example, the app suggests an adjustment (when using Foma 200) for a ten second exposure that gave me 90 seconds! I did use these figures when I first used the films, but I typically cut the suggested times in half these days and get much better results (less like sunglasses densities).
 
PaulBarden said:
I've been using the Reciprocity+ app for iOS on my phone for years. It is generally reliable/accurate. But when I started using Fomapan 100 and 400 in sheet film sizes, I found the "official" reciprocity adjustment values the app gave me were way over the top once I was starting with anything longer than about 3 seconds.
For example, the app suggests an adjustment (when using Foma 200) for a ten second exposure that gave me 90 seconds! I did use these figures when I first used the films, but I typically cut the suggested times in half these days and get much better results (less like sunglasses densities).
Click to expand...
Is that when rating at box speed?
 
Marley's Ghost said:
Is that when rating at box speed?
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For 100 rated at 64 ASA and 400 rated at 250 ASA. That, however, is not enough to account for the absurd overexposure I got using the suggested reciprocity adjustments. Now, I just use FP4 and HP5 adjustments.
 
PaulBarden said:
For 100 rated at 64 ASA and 400 rated at 250 ASA. That, however, is not enough to account for the absurd overexposure I got using the suggested reciprocity adjustments. Now, I just use FP4 and HP5 adjustments.
Click to expand...
Interesting ... I was using 100 in 5x4 rated at ISO 50 a couple of years ago and seemed to get acceptable results treating it like FP4. Just about to pickup some more Foma in 5x7 so I think that's what I'll base things on.
 
Marley's Ghost said:
Interesting ... I was using 100 in 5x4 rated at ISO 50 a couple of years ago and seemed to get acceptable results treating it like FP4. Just about to pickup some more Foma in 5x7 so I think that's what I'll base things on.
Click to expand...
So just to clarify, you meter Fomapan 100 at 50 ISO, then use the reciprocity timer app for Ilford FP4?
I wonder if this would also work with 400 Fomapan. For example 400 rated at 200 and use Ilford reciprocity factor for HP5?
 
That would seem odd because reciprocity for Fomapan falls off a cliff.
 
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