Film Reel Formats

Width
Start be measuring the width of the film in millimeters. If the film is 16mm wide or about the width of your index finger, then you have a reel of 16mm film. 16mm film usually has sprocket holes on both edges, but it’s possible for there to be sprocket holes on only one edge. If the film is 8mm wide, or about the width of a pencil, then it’s either Regular 8 or Super 8 film and you have to look at other details to know for sure.

Center Hub
To tell the difference between a reel of Regular 8 and Super 8 film, look at the center hub on the side of the reel. If you can fit the tip of your pinky finger into the hub then it’s probably Super 8 film, but if the center hub is small then it’s probably Regular 8 film. The size of the center hub is a helpful clue, but it’s not certain. Because Regular 8 and Super 8 film are the same width, it’s possible to store both formats on the wrong kind of hub.

Sprocket Design
For further confirmation that you have Regular 8 or Super 8 film, inspect the sprocket holes on the edge of the film. These small rectangular perforations were designed to feed the film through the camera and projector, and they also reveal the format of the film. Sprocket holes on Regular 8 film are perpendicular to the edge of the film and make smaller image frames, and sprocket holes on Super 8 film are parallel to the edge of the film and allow for a larger image area. The only catch is that the wrong format of leader (usually white blank film at the beginning and end of a reel) can be attached to a reel, so make sure you assess the film and not the leader. It’s hard for the wrong format of leader to be on a film reel, but we do see it from time to time and it’s easy to confirm which format you have.