Reciprocity

2018年09月27日

14.5 MB
文件大小
Android 5.0+
Android OS

关于Reciprocity

计算的曝光时间为波纹管，过滤器和膜的相互作用。

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 CMS 20 II

ADOX PAN 25

ADOX Silvermax

ADOX SCALA 160

AGFAPAN APX 100

AGFAPAN APX 400

Bergger BRF 200

Bergger Pancro 400

Foma Fomapan 100 Classic