How do I compensate for reciprocity failure with Agfa Vista 400 for long exposures?
Asked 12/30/2017
4 views
2 answers
0
I want to make long exposures on Agfa Vista 400 and need to account for reciprocity failure. The film data sheet says no compensation is needed up to 2 seconds, and for longer exposures it gives aperture compensation: +1/3 stop at 4 seconds, +2/3 stop at 16 seconds, and +1 stop at 64 seconds. How can I translate that into adjusted exposure times if I prefer to compensate by shutter speed instead of aperture?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
8y ago
2 Answers
3
I searched for the data sheet. It is linked from the official site here:
http://www1.lupus-imaging-media.com/images/downloads/vista_plus_400.pdf
Section 6 (Long Exposure Compensation) gives straightforward reciprocity failure details:
- No exposure compensation required for exposures up to 2 seconds long
- For a 4-second exposure, you need to open the aperture ⅓ of a stop (or equivalent)
- For a 16-second exposure, you need to open the aperture ⅔ of a stop (or equivalent)
- For a 64-second exposure, you need to open the aperture 1 full stop (or equivalent)
Originally by user38159. Source · Licensed CC BY-SA 4.0
user38159
8y ago
0
Generated from our catalog & community — verify before relying on it.
Agfa Vista 400’s data sheet gives reciprocity compensation in stops, which you can convert to time.
According to the sheet:
- up to 2 s: no compensation
- 4 s: +1/3 stop
- 16 s: +2/3 stop
- 64 s: +1 stop
Equivalent time increases are:
- +1/3 stop = multiply time by about 1.26
- +2/3 stop = multiply time by about 1.59
- +1 stop = multiply time by 2
So the adjusted times are approximately:
- metered 4 s → expose about 5 s
- metered 16 s → expose about 25 s
- metered 64 s → expose about 128 s
In practice, many film cameras make fine adjustment easier with aperture than shutter speed, since shutter times are often in full stops while apertures may allow 1/3-stop steps.
A practical rule from the community answers: you can generally ignore reciprocity failure up to about 1 minute, and for exposures longer than 1 minute, doubling the exposure time is a reasonable approach. Since color negative film is forgiving, bracketing is a good idea if the exposure is important.
Recommended products
UniqueBot
AI8y ago
Your Answer
Related Questions
How do I calculate very long exposures with Ilford film?
Do digital cameras have reciprocity failure on long exposures?
How do the Interfit EXD 400 power numbers relate to stops?
Why won’t a Nikon D5000 auto-expose longer than a few seconds at night?
How does exposure compensation change shutter speed, aperture, or ISO?