Christopher
Stoll

Shooting Expired Film

It would be nice if there was a formula which could prescribe the proper compensation required for any roll of expired film. I started to naïvely work out a formula, but having only 3 data points at the time the task was futile. So, instead, I decided to compile results based upon a system of rules of thumb. These rules of thumb apply to film with an unknown storage history, and assumes the film was probably not stored properly. The rules of thumb will be updated with the results of each new roll.

I have been using the formula ((YYYY + NN/12)-(ZZZZ + MM/12))/FACTOR and rounding to the nearest ⅓ stop. Where:

  • YYYY is the current year
  • NN is the current month
  • ZZZZ is the year the film expired
  • MM is the month the film expired
  • FACTOR is the number of years needed to drop 1 stop (e.g. 1 stop / 25 years => FACTOR = 25).

Black and White

Ilford FP4 125

Rule of thumb: 1 stop / 25 years

  • Expired 1991-01, shot 2022-06 — 1⅓ stops (ISO 50) recommended

Kodak Plus-X pan 125 (PXP)

Rule of thumb: 1 stop / 25 years

Kodak Verichrome pan 125 (VP)

Rule of thumb: 1 stop / 25 years

Kodak Tri-x pan 400 (TX)

Rule of thumb: 1 stop / 20 years

Color

Kodak Ektar 25 (PHR)

Rule of thumb: 1 stop / 20 years

Kodak Vericolor III 160 (VPS)

Rule of thumb: 1 stop / 15 years

Fujicolor Super HQ 200

Rule of thumb: 1 stop / 14 years

Kodak Vericolor 400 (VPH)

Rule of thumb: 1 stop / 8 years