Pushing and pulling film

Pushing or pulling a film is where you under/overexpose your film and ask your lab to develop the film differently than usual to compensate. It is a useful technique to know if you are out shooting one day with the wrong speed film. It is also a good technique to combine with cross-processing.

Pushing film

Push processing is where you give the film more time in the developer to compensate for underexposing the film. For example, you have 400 ISO film, and you need 800 ISO. Shoot as 800 ISO, then ask your lab to push 1 stop. There are side effects though: your contrast will increase, and so will your grain.

  • 100 ISO film shot at 200 ISO is 1 stop underexposed
  • 100 ISO film shot at 400 ISO is 2 stops underexposed
  • 100 ISO film shot at 800 ISO is 3 stops underexposed

Pulling film

Pull processing is where you give the film less time in the developer to compensate for overexposing the film. For example, you have 400 ISO film, and you need 200 ISO. Shoot as 200 ISO, then ask your lab to pull 1 stop. This will result in less contrast that if shot and processed normally. You may not see a reduction in grain, so use the correct speed film in the if you can.

  • 400 ISO film shot at 200 ISO is 1 stop overexposed
  • 400 ISO film shot at 100 ISO is 2 stops overexposed
  • 400 ISO film shot at 50 ISO is 3 stops overexposed

Things to consider

  • With regular print film (C41 process), you can over/underexpose by 1 stop and you may still be able to get usable prints.
  • Pushing colour print film may result in strange colour casts
  • There are some black and white films that are made to tolerate pushing/pulling - for example Ilford HP5+
  • Decreased contrast from pulling may result in flat pictures with little dynamic range
  • Not every lab can push/pull; Pro labs usually can, but most 1-hour photo minilabs cannot