Dream Realization

Pre-dream background

If you have a reel-to-reel device, and want to have the tape to progress at a linear rate, you have to vary the speed the reels spin at because the radial distance is changing. Some recorders didn't have this linear tracking, and tapes recorded on those devices would only sound right when played back on those same devices. That's basically fine because running a tape faster/slower during recording effects the quality a bit but not the mechanics of recording to tape.

The dream realization

If we ever had film reels without linear tracking, that would mean the frame rate would vary as the tape progressed, but also you would need to either vary the film speed (as in how quickly the film reacts to light), or when you developed the film you'd need to adjust how long you were processing the film as you went to compensate, or the film would start dark and get progressively lighter. In my dream I only thought about the first solution but clearly it's way easier to go from pushing the film to pulling it as you process it. I also thought the film would run faster as it got to the end but now that I'm awake I'm fairly certain that's backwards.

Hope this helps.