will someone explain pushing film please?

positivenote · 13-10-2009 9:05am #1

hi guys,
been reading a few times about people 'pushing' film to a quicker speed, can someone expain what this is about and what desired effects it might have on the negs? does the 'push' occur when the film is processed or when its shot?
THanaks and excuse the ignorance

PCPhoto · 13-10-2009 9:11am

have a read of this :

http://photographyguide.org/pushing-pulling-film

and this

http://www.nelsontan.com/articles/pushpull.html
http://www.nelsontan.com/articles/filmdyn.html

and this

http://www.squarefrog.co.uk/holga-techniques-pushingpulling.html

just 'cos the search function is down in boards doesnt mean its down for the rest of the internet. (Not intended to be bitchy)

trishw78 · 13-10-2009 9:12am

I'll try & explain this in the best way possible.

if you have ISO 200 film you decide you don't want to expose as 200 but at 400 you're pushing the film, you also develop it at 400.

if you have ISO 200 film you decide you don't want to expose as 200 but at 100 you're pulling the film, you also develop it at 100.

That's my understanding of it.

CabanSail · 13-10-2009 9:17am

Pushing a Film starts when you are shooting & continues into the development.

Lets say that you have a roll of ISO400 film but want to shoot in lower light. You then expose as if it's a faster film, say ISO1600. If you now processed that film as normal it would be two stops under exposed. In the tank you compensate & leave the developer in longer. This will bring the exposure back to normal, but there will be a lot more grain than if it were exposed at the correct speed. It will probably be more grainy than a film rated at ISO1600 too.

DaireQuinlan · 13-10-2009 10:12am

Adding to what CabanSail said, results also vary wildly depending on what combination of film and developer you're using to do the push. In general though, particularly with extreme pushes, you're sacrificing shadow and often midtone detail to ensure that your highlights get developed properly. So the result is often quite contrasty. Here are a few examples. Developed normally, these films will give you nicely balanced results, here they are pushed a few stops ...

Here's Tri-x (nominally 400) pushed to 6400 and then stand developed in rodinal for an hour. I'd seen good results from this so I tried it. Didn't really work out for me, this was probably the only reasonable shot on the roll ...

Here's delta 100 shot at roughly 400 or so, and then overdeveloped in Ilfosol. Ilfosol is a fine grain developer, so interestingly enough pushing the delta in it didn't make the shots any grainier, but contrast went completely through the roof. The negatives are almost completely transparent with thick blocks of almost opaque emulsion where the highlights are

Nisio · 13-10-2009 12:48pm

Anyone know if the unicare pharmacy processors can do this pushing?

DaireQuinlan · 13-10-2009 1:12pm

Nisio wrote: »

Anyone know if the unicare pharmacy processors can do this pushing?

Nope. Most c-41 places (IE all mini-labs in pharmacys and most photoshops) won't push film. For the most part people wouldn't push C-41 anyway, just silver based B&W. Pushing C-41 often results in wierd colour shifts and increased grain. If I want to shoot 1600 colour I shoot portra 800 at 1600 but just develop it normally and compensate when scanning. There's a bit of latitude there for underexposure.

will someone explain pushing film please?

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