Best films to push/pull?

[jasonjoo]

*Edit* I just realized how misleading my title could have been. I do not mean push/pulling during development. Not sure if there's a term for what I've mentioned below, but hopefully people will be able to understand my gibberish

Hello folks!

I'm not sure how often this is asked, so please forgive me if it has and point me in the right direction!

I've been shooting a few different types of film lately. Haven't processed them yet (I'll be developing some negatives tonight! Wish me luck!). So far I've shot Acros 100, FP4, Delta 400, Delta 3200, and TMY400. While going through some photos and through the forums, it seems like people often expose their negatives at a different ISO then the film speed actually is.

The one I see most often is people exposing Delta 3200 at 1600. I guess this follows the "expose for the shadows" and "develop for the highlights" rule, but is there any other reason for this? When developing, do these people develop at the normal development times as if the film was rated at 3200? I've also seen some people shooting ISO 400 film at ISO 3200. Not sure which particular film they used, but I would be interested in which one is best for doing this. Also, how grainy would the negatives produce (35mm and 120)? Would it be grainier than Delta 3200 or do both films produce completely different characteristics?

People also mention EI, which I *THINK* is Exposure Index. What exactly does this mean?

Sorry for so many questions! I'm really just bursting at the seams with them, but I'm holding back

Thanks for your help,

Jason

 

[Mark Antony]

Films have ISO speed which is the amount above base fog needed to register exposure (I'm sure I'll be corrected if I've stated that wrong)
ISO is basically the manufacturers recommended speed.
EI on the other hand is 'exposure index' which in the Delta 3200 example is its box speed.
Delta 3200 is a film designed to be pushed beyond its ISO which is 1000.

With other films like say Tri-X people often deviate from the ISO (400) to use personal EI ratings which can differ slightly depending on developer/agitation and even camera combinations
here is an explanation (it seems ok although I've not read it)
http://www.pacmclaurin.com/No-Zone System-2006.htm

Hope i've not confused you (too much)
my favourite film Neopan 400 I rate at 400 and process in Microphen, if I use dilute Rodinal (1:50) I rate at EI 320.
I'm sure other will explain better,
Mark

 

[AgX]

ISO, ASA, DIN etc. give speeds related to a certain standardized procedure. Within time the shape of the charateristic curve got a major role in these procedures.

However sometimes these procedures cannot be applied or a different outcome is welcomed.
Then an EI is applied.

 

[lns]

I would recommend reading a good introductory book like Ansel Adams's The Negative, or Henry Horenstein's Black and White Photography. Both books helped me to understand the basic theory. There are a lot of other good ones too. Good luck! -Laura

 

[jasonjoo]

I did borrow a copy of the Negative by Ansel Adams from the library. I haven't had a time to read much of it, but a lot of it does go over my head! I'll have to pay more attention. Not typical leisure reading

Thanks for the help guys.