Reciprocity

Based on the film that you are using and the metered exposure time, calculate the exposure time to use to correct for the reciprocity correction and optionally the filter factors of the filters and the correction for the bellows extension that you might be using. Supports now also shutter speeds from 1/1000 seconds.

All information is contained in the App so no data connection is needed when you’re on a photo shoot abroad, on top of a mountain or in the deep countryside without any connectivity.

Normally there is a reciprocal relationship between light intensity and exposure time, but typically when exposure times get up to about 1 second or longer, this relationship breaks down. This is the so called Schwarzschild Effect and longer exposures are required to compensate for this or you'll risk underexposing your negative. Each film has different characteristics and this tool will calculate the exposure time to use based on the film and the metered exposure time.
The formulas used in this tool are taken from the film manufacturers' supplied data sheets and from the excellent Black-and-White Reciprocity Departure Revisited article by Howard Bond in the Photo Techniques magazine.


Currently, reciprocity failure information about the following films is included:
ADOX CHS 25
ADOX CHS 100 II
ADOX PAN 25
Bergger BRF 200
Foma Fomapan 100 Classic
Foma Fomapan 200 Creative
Foma Fomapan 400 Action
Freestyle Arista EDU Ultra 100
Freestyle Arista EDU Ultra 200
Freestyle Arista EDU Ultra 400
Fuji Neopan 100 Acros
Fujichrome Provia 100F
Fujichrome Velvia 50 [RVP50]
Fujichrome Velvia 100 [RVP100]
Fujichrome Velvia 100F [RVP100F]
Fujicolor PRO 400H
Ilford Delta 100
Ilford FP4 Plus
Ilford HP5 Plus
Ilford PAN-F Plus
Ilford SFX 200
Ilford XP2
Kodak Plus-X
Kodak Portra 160
Kodak Portra 400
Kodak PROFESSIONAL T400 CN
Kodak T-MAX 100
Kodak T-MAX 400
Kodak T-MAX 3200
Kodak Technical Pan
Kodak TRI­-X 320
Kodak TRI-­X 400
Read more
3.9
40 total
5
4
3
2
1
Loading...

What's New

= Reworked the application. The interface includes the details of the calculated exposure time; tap the calculated exposure time to see how many stops were added for filters and for the bellows used and how many seconds were added to correct for the reciprocity failing.
= Added reciprocity information for more films, most notably included Kodak Portra 160 and Kodak Portra 400.
= Added a timer to use the same app for the calculation and the timing of an exposure.
Read more

Additional Information

Updated
July 30, 2017
Size
19M
Installs
1,000+
Current Version
4.1
Requires Android
4.0.3 and up
Content Rating
Everyone
Permissions
Offered By
Hans ter Horst
©2018 GoogleSite Terms of ServicePrivacyDevelopersArtistsAbout Google|Location: United StatesLanguage: English (United States)
By purchasing this item, you are transacting with Google Payments and agreeing to the Google Payments Terms of Service and Privacy Notice.