question on push pull film

[haagen_dazs]

hi
i had some questions on push pulling film.
at which stage does this happen?
is this process done during the development of the negatives in all the chemicals or is it done during making of the prints?

[Revolucion Artistico]

The rating on the box of the film is a suggestion on the film's "best" rating. You can push or pull most films although the outcome will differ. Just set your camera or meter's ASA setting to the speed you want to shoot it at and then develop it according to that speed. The box might have directions about dev. times for different speeds or else check a site like www.digitaltruth.com. There are also developers which are made to help increase the speed of certain films like Ilford Microphen.

[haagen_dazs]

i am a newbie so pardon these questions
so it seems that push pull is done during developing
i am trying to find out a workflow i could use

i am assuming that the shops that use the roller transport system will develop the film at the box speed right? Come to think of it, I never asked coz i am not sure if they push pull film at these 1hr shops...

1) I could use a ISO400 film, shoot it at ISO400, develop it at the 1hr shops at the 400 speed rating and scan them and tweak the curves on the image film to make my film brighter/darker/contrasty....

2) I could use a ISO400 film, shoot it at ISO 320 or 2xx, develop it at the box speed, and scan them. it should be brighter. (i like of like prints brighter and less dark shadows)

3) I could use a ISO 400 film, shoot it at ISO320 and develop it at that speed (probably have to do this at a pro lab)

Basically i haven't done (3) before. What will that outcome be?
What is advisable?
what is the difference between (2) and (3)?

[40oz]

When I push film, I do so by at least two stops. The difference in contrast/grain at only a half-stop is minimal, I would even say it falls within the margin of error when developing by hand.

If you don't want to develop traditional B&W at home, or you wish to use C41 films, you might experiment with over-exposing up to a stop and having it developed normally to see the results from the lab machine. Some people swear by over-exposing C41 film as a general habit. Modern negative films tolerate exposures within one stop quite well, rarely ruining an image.

I'm sure the machines at most 1 hour places can push/pull film, but you'd have to ask the operator when you dropped off the film to know if the operator knew how to do it.