Pack film cameras were mostly equipped with automatic exposure, but still had to be focused and a flash bulb or cube unit needed to be used with colour film indoors. The development of the film required the photographer pull two tabs, the second tab which pulled the positive/negative "sandwich" from the camera, where it developed outside the camera. If the temperature was below 15 °C (60 °F), the positive/negative "sandwich" was placed between two aluminum plates and placed either in the user's pocket or under their arm to keep it warm while developing. After the required development time (15 seconds to 2 minutes), the positive (with the latent image) was peeled apart from the negative.