Reciprocity of Fomapan or Arista Ultra

[Jim Noel]

Does anyone have a reciprocity chart for these films, particularly 100? The manufacturer doesn't have one on the sight. From what I have read, the reciprocity is not the same as typical films.
Thanks,
Jim

[Jimi]

Have a look here, under the heading "Schwarzschild effect": http://foma-cz.cs4.cstech.cz/en/fomapan-100 - that's a starting point at least.

[peter schrager]

I'm pretty sure you will that info on apug
I do have it written down for the 100 and 200 films but not on my computer

[Pere Casals]

A very, very high LIRF... 3 stops correction for metered 10 seconds....

[devb]

I forget where I found these corrected times. These were advertised for Arista EDU 200, which I successfully used despite the fact that the film in the 200 box was actually Arista EDU 100. I'm almost impressed by how extreme and inconvenient these are.

In seconds:

1 = 3
2 = 9
3 = 16
5 = 33
8 = 65
10 = 90
13 = 131 (2' 11")
15 = 160 (2' 40")
20 = 223 (3' 43")
25 = 326 (5' 26")
30 = 418 (6' 58")
40 = 612 (10' 12")
50 = 814 (13' 34")
60 = 1018 (17'00")

[Jim Noel]

I forget where I found these corrected times. These were advertised for Arista EDU 200, which I successfully used despite the fact that the film in the 200 box was actually Arista EDU 100. I'm almost impressed by how extreme and inconvenient these are.

In seconds:

1 = 3
2 = 9
3 = 16
5 = 33
8 = 65
10 = 90
13 = 131 (2' 11")
15 = 160 (2' 40")
20 = 223 (3' 43")
25 = 326 (5' 26")
30 = 418 (6' 58")
40 = 612 (10' 12")
50 = 814 (13' 34")
60 = 1018 (17'00")

Thanks. These should be helpful.
Jim

[Maris Rusis]

Here's an excerpt from practical testing of Fomapan 200. The actual results do not match the extremely pessimistic numbers from the manufacturer's "guesswork".

Fomapan 200 reciprocity characteristics are supposed to be easy to test for so I tried. Well it wasn't so straight forward but three 120 rolls later here are some results:

The exposure level I chase in landscape metering is Zone IV = shade side of tree bark, dark rocks, etc. The question becomes "what exposure time extensions must I give for long exposures so I get the same negative densities for Zone IV as for short exposures?" Answers obtained:
Measure 1 second on the meter...give 1.5 seconds
Measure 2 ... give 4
Measure 3 ... give 7
Measure 4 ... give 12
Measure 6 ... give 18
Measure 8 ... give 28
Measure 10 ... give 40
Measure 14 ... give 48

For photographs of dark scenes I don't apply the full reciprocity correction. I want the final picture to match the scene with empty black shadows, subdued mid-tones, and a few gleaming highlights. Remember also that the shadow parts of the scene will invoke reciprocity failure in the film but the highlights won't. Extending exposure causes a strong increase in contrast but this can be controlled by reduced development. But reduced development can cause a loss of film speed which calls for even more extended exposure; and so on. It is not so simple to make dark scenes look like bright scenes!