Black & white film developing manual test

Sometimes the manufacturer gives no official time, and our developing time calculator has no figure either. In that case you can find the time yourself with a development test.

How to test

• Cut a test strip of film and immerse it in the developer.
• Time how long it takes to turn completely dark.
• Divide this time by three to estimate the full development time.

Example:

If a film strip darkens in 17.02 seconds, divide by 3 is 5.67 which means 5 minutes 40 seconds is the estimated development time.

This process was first published by Lomography, & Parrino, E. (2021, December 22). How to find your developing time for any black & white film. Lomography. https://www.lomography.com/magazine/347678-how-to-find-your-developing-time-for-any-black-and-white-film