Pre and Post Exposure Question

I have pre-exposed slide film to control contrast, it work well enough. You simply aim it, out of focus, at something uniform and featureless (e.g. the sky, some concrete, a piece of paper) and expose it 3 stops faster than your main exposure will be.

There is a calibrating gizmo (expodisc), normally used for white-balance control, but you can put one on your lens and preflash with it as well:

http://www.expoimaging.net/MediaFiles/instructions/EN_16.pdf

(You could make yourself an expodisc out of something translucent)

You could also preflash your slide film in the darkroom.

I never tried preflashing c41 films, since they have so much range anyway. If I really expected problems with contrast I'd simply rate the film at box speed or a wee bit faster, and/or use a graduated neutral density filter, etc....

 

hi christopher

to build upon what keith suggested ..

http://www.apug.org/forums/forum37/6968-pre-exposing-flashing-film.html

it has been years since i posted that thread
and i haven't done it yet

good luck!

john