Quote Originally Posted by 36cm2 View Post
Am I correct that, when one extends exposure time due to bellows extension and then extends exposure time again due to film reciprocity failure, the recommended reduction of development time is intended to offset increased contrast arising from reciprocity failure (and not from bellows extension). ...
You are correct.

Quote Originally Posted by 36cm2 View Post
... Also, what are the general guidelines for how much to reduce development time to compensate for reciprocity failure? ...
See attached, but these are theoretical values. In practice, the contrast increase is not as high as exposure differences would indicate. I've never figured out why that is.