Push / pull processing
Rate your film off box speed, then adjust development to match. These are widely-used starting factors — always confirm against your film and developer.
Pushing raises contrast and grain and blocks shadows; pulling lowers contrast. Colour negative pushes less cleanly than B&W. Cross-check the Massive Dev Chart for your exact combo.
About this tool
Rate a film away from its box speed and you must change development to match. Enter the box ISO, the base development time and how many stops you are pushing or pulling. The calculator returns the new exposure index you should meter at, plus an approximate adjusted development time for pushing longer or pulling shorter.
How to use it
- Enter the film's box ISO and its normal base development time.
- Enter the number of stops to push (positive) or pull (negative).
- Read the new exposure index to meter at, and the approximate adjusted development time.
FAQ
Is the adjusted development time exact?
No, it is an approximation. Push and pull response varies by film and developer, so treat the result as a strong starting point and refine it against your own tests, especially beyond one stop where shadows and highlights shift.
What actually happens when I push film?
Pushing means underexposing at a higher EI, then developing longer to build density. It raises contrast and grain and loses shadow detail. Pulling does the opposite: overexpose, develop less, lowering contrast.