Kodak DX codes and pushing

[bblhed]

I put this in the color film category because there is no general film category, if it is in the wrong place please move it so I know where it should have been.

My question: The other day someone posted about adding DX codes to their bulk load cassettes and they posted a link to a DX decoding chart and that got me thinking. Kodak Gold 400 film has a DX code on it that says it can be pulled 1 stop and pushed 3 stops without changing the processing same with 400TX. So if I am reading this right I should be able to shoot these films at ISO 3200 and get printable results, I assume my prints would have a lot of grain, but still be printable.

Is this crazy talk, am I reading something wrong, or is it true that you can shoot Kodak ISO 400 consumer film at ISO 3200 and get acceptable prints from it? I assume results would be better the closer you got to box speed, but I am wondering if you can really push it that far with acceptable results. If this is true, all I can say is wow.

Thank you for setting me straight and not banging me over the head with a stick, I looked and couldn't find a thread where someone mentioned this before.

 

[Paul Sorensen]

I don't know about DX codes, I do know that Kodak's datasheet for TX indicates that one stop pushing requires no changes in developing and that further pushing does require changes to the development times. Here is that datasheet:

http://www.kodak.com/global/en/professional/support/techPubs/f4017/f4017.pdf

As for pushing in general, you will certainly hear from folks here that there is no such thing, and I tend to agree in theory. you will always lose some shadow detail and the further you push it, the more you lose. All push processing does is to make the best of underexposure.

 

[Paul Sorensen]

Oh, I just found something on line about DX codes, you are reading it backwards. The code for 400TX and apparently for 400 speed consumer films indicates that you can pull the film 3 stops, not push. Pushing would only be one stop. This does match the Kodak datasheet for TX, which has pushing times only for 1600 and above. Remember, pushing is underexposing, so -1 is pushing one stop, +3 is pulling three stops. Negative film is generally a lot more forgiving to overexposure than underexposure, so this does make sense to me.

 

[bblhed]

Oh yeah, I forgot to post this http://en.wikipedia.org/wiki/DX_encoding how to read DX encoding it is intresting to see what that cassette is telling your camera, and the processing machine.

 

[bblhed]

DOH, I was reading the + as more, I should have been reading it as less. Alright, I was wrong and I now know better so I guess I did learn something.

As for there being no such thing as pushing or pulling, there are two ways to look at it, you can call it pushing / pulling, or you can call it an exposure mistake, it's the same thing if you think about it.

 

[MattKing]

"push" and "pull" don't refer to exposure at all. They refer to adjustments to development.

I think you are actually referring to under-exposure and over-exposure.

The data for the film indicates that you will get reasonable results from scenes with average contrast and range of brightness if your exposure is anywhere between one stop under-exposed and three stops over-exposed.

All the DX codes do is automatically communicate the film sensitivity (and length and process) to the camera and development machinery.