Analog film photography and cameras

since the canonet use the old battery, the newer battery is slighty more powerful and will overexposed the image a tad, this can be solved by simply changing the ISO on the camera, if your film is 100 ISO, set the camera to 200 ISO and you'll be fine (if you use the new battery).

I've been reading about this. I've put in an air cell hearing aid battery, its 1.4v compared to 1.35 for the original mercury so hopefully wont make a difference.