SUMMARY
Expired film presents unpredictable results in photography, with its usability depending on age and storage history. Cold storage significantly extends a film's life, while heat, humidity, and X-rays can degrade it. The general rule of overexposing one stop per decade applies differently to film types; black and white negative film handles this better than slide film, which is prone to color shifts that overexposure cannot correct. Understanding these factors is crucial for potentially salvaging rolls with unknown histories.
TAKEAWAYS
Expired film's quality depends on age and storage conditions.
Overexpose negative film by one stop per decade, adjusting for film speed.
Expired slide film often color shifts and is not fixed by overexposure.
Cold storage is key to preserving film longevity.