Saturday, January 12, 2013

Push Processing Kodak BW400CN Film

Iron Horse Trail by Wayne-K
Iron Horse Trail, a photo by Wayne-K on Flickr.

I love the convenience of C-41 processed B&W film like Kodak BW400CN because it can be processed at the local drugstore, or in my case, the local Mike’s Camera (former Wolf Camera in Dublin, CA). I have the film developed and scanned to CD and Mike’s Camera will have it completed in only an hour. I’ve been shooting Kodak BW400CN film for almost two years now and learned the film looks best over-exposed by a stop, with the exposure adjusted when the negative is printed or scanned. Color negative film (and B&W film that’s processed in color chemicals) have a large exposure latitude, meaning one can under or over-expose it by quite a bit and still have usable prints. The drawback of under-exposure is the shadow areas become muddy/grainy looking. Over-exposure, on the other hand, yields very clean shadow areas. Given these film characteristics, I intentionally over-expose Kodak BW400CN to get cleaner shadows.

During my last visit to San Francisco, I planned on doing some street photography with my Nikon FM2 film camera loaded with Kodak BW400CN film. However, I found the ASA 400 film a bit too slow for the city because San Francisco is largely shaded by tall buildings. ASA 400 film doesn’t allow me to use fast enough shutter speeds on moving subjects. I researched BW400CN film on the Internet and found it does well push-processed to ASA 1600. I decided to experiment with a test roll. Push processing involves shooting a film at a higher speed than it’s rated and then developing the negative in the chemicals for a longer duration to compensate for the under-exposure. In my case, I shot the BW400CN film with my camera set to ASA 1600 (which under-exposes the negative by two-stops). When I dropped the film off at Mike’s Camera, I asked them to push-process the roll by two stops.

Overall, I was very pleased by the results. There’s a bit more grain in the photos than if I had shot it at its rated ASA 400, but not as much as I expected. Given the exposure latitude of the film, I could have requested “normal” processing (standard development times), but I think the final result would have been much grainier and muddier.

Here are a few photos from my first push-processed roll of Kodak BW400CN film.

Leaf on the Iron Horse Trail


Frosty Leaf


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