This thread is in the 35mm cameras and accessories so I assume that is what you have. Remember that the ZS was designed for LF cameras or other cameras where every shot could be developed individually. While there are some principals that can be applied with a roll film camera the vast amount cannot unless you shoot the entire roll on one subject. This is possible if you roll your own and roll short strips. When I shot 35mm and had a darkroom available I would bracket each scene. +1-0-(-1). Sometimes would go as far as 2 stops either way. Have fun.