If you look closely at any roll of 35mm film, you will most likely see an expiration date. This is because the layers of chemicals on each roll start to degrade over time. Don't worry if you just bought film from the store - this process takes many years to happen! (If you want to keep your film fresh, store it in a refrigerator)
Every roll of color film consists of layers of emulsions that respond to different areas of the color spectrum. As these different layers start to degrade you can get some very cool color shifts.
If you ever find an old, expired roll of film at a thrift store or online, we recommend giving it a shot!
What to expect when shooting expired film?
Always treat shooting expired film as an experiment. Yes, you can get some amazingly artistic results, but you also risk your photos not turning out at all. It is all part of the fun!
Expect strong color shifts towards green or red in your photos. Graininess will be increased and the contrast will be decreased.
Tips for shooting expired film
The general rule of thumb for shooting expired film is to overexpose the film by one stop for every decade that the film has been expired.So, if you have a roll of ISO 400 film that is 10 years expired, you should shoot it at ISO 200. If that same roll of film were 20 years expired, you should shoot it at ISO 100. Keep adding one stop of overexposure for each 10 years of expiration.
There is no guarantee that this technique will result in a cleanly exposed image, but it is a great place to start. Keep an open mind and have fun!