| My word - a discussion about film speeds and processing. Whatever next?
Any way, if you underexpose film (Tri-X at 1600 ASA instead of 400 was common for sports on our rainy, dull little island) then you push it in processing, which means extending the development time to compensate. The result is a negative that's almost as good but not quite, with bigger grain. Similarly if you over expose film you pull it, develop for less time, resulting in a decent neg with - depending on your film stock - less grain.
That's the theory, though colour neg films had so much exposure latitude that you'd get a decent print if the exposure was three stops out, and as for black and white, a good craftsman (Not me, I was always cr*p at it) could get a print from just about anything. Colour tranny was more pernickety, a stop either way was about it, erring on the under side for printing and over side for projection if necessary. |