on 6/21/01 7:37 PM, Arthur Entlich at artistic@ampsc.com wrote:
>> I use a lot of this film pushed to +3 stops..according to Kodak the resulting
>> ASA numbers are 200 (normal), 320, 640, 1000. Even at 1000 it still has very
>> low
>> grain (a bit less than a 400ASA print film), of course you have to be careful
>> since it will not tolerate improper exposures at ASA1000. Pushed +3 its a
>> good
>> film for available light photography. Extremely fine grain when used at 200
>> or
>> 320.
>
> OK, now I'm confused. I thought taking ASA 200 film up three 'stops'
> meant 200 to 400 to 800 to 1600 ISO/ASA. As I understood "stops" it was
> an additional f-stop. I thought each "full" f-stop more open increased
> the amount of light reaching the film by a factor of 2, which was also
> equivalent to one shutter speed position lower. So, if I had a 200 ASA
> film without any pushing, and the perfect expose was 1/125th sec at
> f/5.6, that I could also take this same image at either 1/250th sec at
> f5.6 or at 1/125th sec at f4.0 if I had the film push processed for one
> additional stop, and so on.
you were going pretty good until the last bit. If you pushed the film a
stop, you could used 1/250 @ f/5.6 or 1/125 @ f/8 NOT f/4.
--
John Brownlow
