What are the most important considerations when using expired film stock?

1 Storage conditions

The way expired film stock has been stored can affect its performance and quality. Ideally, you want to use film that has been kept in a cool, dry, and dark place, away from heat, moisture, and light. These factors can accelerate the chemical degradation of the film, resulting in color shifts, graininess, fogging, or loss of contrast. If you are not sure about the storage history of the film, you may want to test a small sample before using it for your project.

3 Exposure and development

When using expired film stock, you need to adjust your exposure and development settings accordingly. Expired film tends to lose sensitivity over time, which means you need to overexpose it to compensate for the loss of light. The amount of overexposure depends on the age and condition of the film, but a common rule of thumb is to add one stop of exposure for every decade past the expiration date. For example, if you are using a 200 ISO film that expired 20 years ago, you should treat it as a 50 ISO film and expose it accordingly. Similarly, you may need to extend the development time or use a stronger developer to achieve the desired contrast and density.

4 Expectations and experimentation

One of the most important considerations when using expired film stock is to have realistic and flexible expectations. Expired film can produce unpredictable and inconsistent results, which may or may not suit your artistic vision and style. You may encounter color shifts, faded tones, increased grain, reduced sharpness, or other defects that can enhance or ruin your images. Therefore, you should embrace the element of surprise and experimentation that comes with using expired film, and be prepared to accept or reject the outcomes. You may also want to use expired film in combination with other techniques, such as filters, cross-processing, or double exposures, to create more interesting effects.