# push/pull for overexposed film



## rbailey23 (Apr 7, 2013)

I accidentally shot a roll of triX B/W 400 at 200 ASA.  Since overexposed shots come out brighter, I would think it would be better to develop the film LONGER, since that makes them darker/ higher contrast. But most sites tell you to do the opposite, and I don't understand why.


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## gsgary (Apr 7, 2013)

You develope them for less time thats how pulling works


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## Helen B (Apr 7, 2013)

Overexposing negative film means that the image on the film will be darker, not lighter (it will only look lighter after it is reversed during printing). Therefore you want to develop less, to reduce the amount the film darkens in the developer.

It is the same for regular reversal (slide) film, because that is first developed to a negative.


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## timor (Apr 7, 2013)

rbailey23 said:


> I accidentally shot a roll of triX B/W 400 at 200 ASA.  Since overexposed shots come out brighter, I would think it would be better to develop the film LONGER, since that makes them darker/ higher contrast. But most sites tell you to do the opposite, and I don't understand why.


Hi and welcome here. Do not wonder, your thinking is pure digital and film has nothing to do with that technology. It operates on different principles based on real light absorption and if your film absorbed too much the only way to mitigate it is to reduce the development and not to use all of that absorbed light and get the negative in proper optical densities. Over exposure is done routinely by photographers seeking reach and less contrasty negatives.


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## duhast (Apr 7, 2013)

rbailey23 said:


> I accidentally shot a roll of triX B/W 400 at 200 ASA.  Since overexposed shots come out brighter, I would think it would be better to develop the film LONGER, since that makes them darker/ higher contrast. But most sites tell you to do the opposite, and I don't understand why.


Here's what is going on with film...

The emulsion of the film (the light sensitive part) is made of silver halide crystals. Silver halide changes when exposed to light, the more light, the more change. It is the developing process that completes the change of the crystals, and the 'fixing' process that removes all the unexposed crystals, leaving you with a photo negative. There is latitude, range, in all of this process. Time is a factor, so developing time is going to change the halides more or less depending on how long the time is.

So, film that has been overexposed, in your case one stop, is going to look more and more overexposed the longer the development time goes. Those halides that were hammered by light will just continue to cook and cook and cook with longer development. On the other extreme, if you used an ridiculously short development time, like 30 seconds, you would end up with film that would look grossly underexposed, despite the fact that the exposure is +1.

The famous Zone System of exposure has a basic rule that you 'overexpose and under-develop'. This gives you shadow detail and un-blown highlights.

So if you are going to develop that film, do the time/temp calculations to develop it minus 1, that should give you film that is like it was exposed at 400.


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## rbailey23 (Apr 7, 2013)

how can I rate the development down a step? I typically do 9:45 in d-76 1:1 ratio

btw i do not own a digital camera and it is not "digital thinking" .


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## Helen B (Apr 7, 2013)

There is a Kodak tech note for D-76: http://www.kodak.com/global/en/professional/support/techPubs/j78/j78.pdf but it only mentions pushing, as does the tech note for Tri-X. The massive dev chart is good for guide times for pulling: B&W Film Developing Times | The Massive Dev Chart

Compare those times with the time you like for exposure at ISO 400 to arrive at a suggested time for EI 200.


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## timor (Apr 7, 2013)

rbailey23 said:


> btw i do not own a digital camera and it is not "digital thinking" .


My apologies, too many kids around cannot figure out film technology. Maybe for better understanding principles of film photography can you take a look at this ?
http://lit.lzicka.eu/Black.and.White.Photography.(2005),.3Ed.(036373052).LotB.pdf
It is a book by Henry Horenstein, a good American photographer and scholar.


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## rbailey23 (Apr 7, 2013)

yikes, if i'm reading the massive chart correctly, it looks like the only difference between developing at 400 iso and stopping down to 200 is 15 seconds. That means i would be clocking at 9:30 instead of 9:45. that's hardly a difference at all.


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## timor (Apr 7, 2013)

Here you go.Tri X has huge tolerances, but I would cut rather 30 sec.
Here something to read abot it:
http://photo.net/bboard/q-and-a-fetch-msg?msg_id=001YOW
http://www.apug.org/forums/forum37/39395-pulling-tri-x.html


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## compur (Apr 7, 2013)

rbailey23 said:


> I accidentally shot a roll of triX B/W 400 at 200 ASA.  Since overexposed shots come out brighter, I would think it would be better to develop the film LONGER, since that makes them darker/ higher contrast. But most sites tell you to do the opposite, and I don't understand why.




When you set your camera to a low ISO, you are telling the camera, "this film is not very sensitive to light," so your camera gives it more exposure. Then, since it got more exposure, it will need less development to bring out the image.


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## rbailey23 (Apr 7, 2013)

After doing a little reading I am realizing that the pull process will  cause the photo to lose contrast. I wonder if I would be better off  pulling the film and using a higher contrast filter in the enlarger? or  just developing the film normally and using a lower contrast filter....? note that i was shooting in clear daylight.


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## timor (Apr 8, 2013)

rbailey23 said:


> After doing a little reading I am realizing that the pull process will  cause the photo to lose contrast. I wonder if I would be better off  pulling the film and using a higher contrast filter in the enlarger? or  just developing the film normally and using a lower contrast filter....? note that i was shooting in clear daylight.


As I said before, shorten the development just by a little, if you don't your highlights might be hard to print (they will be dens). You will not loose too much of a contrast, maybe half a filter value. You may also use more contrasty paper developer or add for that occasion 1/2 g of potassium bromide to your regular one. You may also try compensating development. Over exposing TX by one stop is not such a big deal thanks to its large latitude.


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## Josh66 (Apr 9, 2013)

rbailey23 said:


> yikes, if i'm reading the massive chart correctly, it looks like the only difference between developing at 400 iso and stopping down to 200 is 15 seconds. That means i would be clocking at 9:30 instead of 9:45. that's hardly a difference at all.



The Massive Dev Chart is usually a good starting point, but it's not the bible.  The times listed there may not be to your liking.

I push much more often than pull, but a 15 second change in dev time sounds pretty insignificant to me...

Personally (this is totally just a guess - I would do a test roll before trying to develop anything important), if your normal time was 9:45, I would try something like 8 minutes.

What developer are you going to use?


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## bsinmich (Apr 11, 2013)

You are only 1 stop off on correct exposure.  The latitude of the film will not be a problem at only 1 stop.  You will have minimal problems at normal development times.  There is that much variation many times within a single photograph.  Cut a few seconds off development time and you should be safe.


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## timor (Apr 12, 2013)

Just wondering if we will know ever what happened with OP film ?


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## gsgary (Apr 12, 2013)

It's probably gone tits up


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## timor (Apr 12, 2013)

gsgary said:


> It's probably gone tits up


Probably you're very right. It's possible he posted same question on every film forum he could find, got his answers and little chance to see him back.
On the other hand I am under a strong impression, that most of this young adepts of photography think, that film works just like digital and that there is only one right answer to a problem. This things are happening if one names two totally different technologies with the same name. Confusion arises from thinking that the new is a natural extension of the old one. Well, film doesn't play by numbers, film might be you friend if you know it well enough and long enough. One shot try-outs are like licking lollipop thru a packaging. On the other hand world accelerated beyond speed of "any" film.


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## smithdan (Apr 12, 2013)

Could have used this knowledge many years ago.  Big shots visiting, photos needed, friend shot and I agreed to process and print.  Buddy drops off the roll, Tri X shot in error at 125.  Needed decent prints for presentation as well as ones with enough contrast to cut Gestetener stencils.   One roll, one shot at it.  Remember that they wern't pretty..


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## compur (Apr 12, 2013)

As the OP said, "Since overexposed shots come out brighter..." indicates unfamiliarity with the concept of a negative.  That is, an overexposed negative comes out "darker" (denser) not "brighter" as a digital image would.


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## timor (Apr 13, 2013)

Yet he denied "digital thinking" (no digital camera). If he is 18-20 years old today, I am afraid that he doesn't know any other "thinking", anyway nowadays everyone owns and shoots (me to) digicam, in the cell phone. Hey, that's a big part of social "networking", to send images etc. I have to admit I started my photographic hobby I was 16 and I wanted to be in my circles "the guy with the camera", then it was more "unique"; shoots, processes and brings prints. It changed into personal passion later. Maybe OP wants to be "original" in his circles by shooting film and hit the snag. If he is ambitious or think it is worth it, he will overcome, but knowing how easy going is young generation and accustomed to getting everything ready on the plate I give only 20 % chances for that. I have already this experience. Eh...


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