Pushing by Altering DX?

[bvy]

This might sound like a naive question, but here goes. I underexposed some color film (Kodak Gold 100). I normally get my film developed at the photo lab at Target (US department store). The ladies there are so nice -- God bless them -- and they do a respectable job processing the film. But I could never explain push processing to them, if their machines are even equipped to do such a thing. Is it possible to alter the DX coding of the film cassette to have the film pushed by one stop?

 

[Prof_Pixel]

Is it possible to alter the DX coding of the film cassette to have the film pushed by one stop?

No ... but if your underexposure is just 1 stop you should be OK.

 

[hrst]

No, C-41 is a standard process with a standard processing times for every film, so they are not interested in your DX codes. The machines probably support push processing if the operator knows how to do it.

That being said, push processing does not do miracles. You are usually fine even without it, and if you are not, then the push processing probably wouldn't have saved the day either.

 

[BrendanCarlson]

Do you just want the film to be shot at 100 and then processed for +1 stops?

 

[bvy]

Thanks everyone. A little more research and I see that most C-41 negative films, regardless of speed, are developed for the same amount of time -- and that pushing involves increasing the development time. So making 100 speed film look like 200 to the processor/lab wouldn't be the equivalent of pushing one stop. For that matter, what effect would it have? Sounds like none at all.

Brendan, I've already shot the film. It's Kodak Gold 100, and I shot it in a camera with a fixed shutter speed and aperture. I know that I was shooting in lighting conditions that called for 200 or 400 speed film, but I got tired of waiting for the sun. Also, the film is very expired. Being able to push it a stop or two would have been nice.

 

[hrst]

Thanks everyone. A little more research and I see that most C-41 negative films, regardless of speed, are developed for the same amount of time -- and that pushing involves increasing the development time. So making 100 speed film look like 200 to the processor/lab wouldn't be the equivalent of pushing one stop.

Push processing never increases real film speed that much. It increases contrast and brings your underexposed MIDTONES to the correct level, but your underexposed shadow details remain as blocked as they were before. It is often stated that 1 stop push gives 1/3 stop of real film speed extra, and 2 stop push gives 1/2 stop, and that's the limit.

Push processing is NOT a proper counteract to underexposure at all. Underexposure gives a certain effect and push processing gives another kind of effect, and these effects are not even near to opposite to each other. Often, underexposure and push processing are combined to give higher working exposure index but this is very different from choosing a higher-ISO film to begin with. Underexposed, push processed images have a feeling of blocked shadows, high contrast and high grain.

Now, with your film being expired, it has lost some speed and gained some fog. Push processing also increases fog so it doesn't really solve the problem. The only solution to expired film is to overexpose.

So, just develop it normally and see what you can get out of it. It's not going to come out any better, or much better from push processing. Depending on how expired it really is, the result may still be very well usable.