@grainydays Jason demonstrates how a popular but controversial “rule” helps him make good exposures on expired film.
“The Rule” dictates that you should over-expose your colour-negative film by 1 stop for every decade it’s been expired. Not everyone agrees with this prescription, but Jason showed that it worked (at least in his experience).
For example, an ISO 200 colour-negative film that expired in 1994 is 3 decades past its prime so it should be metered like ISO 25 (200 — 1stop = 100 — 1stop = 50 — 1stop = ISO 25).
Jason takes “The Rule” a little further by suggesting to add 1/2 stops for every stop the film stock is faster than ISO 400.
So, an ISO 800 colour-negative film that expired in 1994 should be metered like ISO 100 — (1 × 1/2stop) = ISO 66, which can be rounded to ISO 50.
For black-and-white film, Jason suggests over-exposing by 1 stop for every 20 years past its expiry date.
Finally, the expired slide film should be shot at box speed and prayed for, which seems to have worked out for Jason as well. However, he did show some bad results when he tried to cross-process Kodak Ektachrome 64T in C-41 chemicals.
Dmitri Jun 11, ‘24