The Polaroid sync control that you described was their "economy" model, designed for smaller theatres. It was wired between the two selsyn motors, and allowed the opertor to advance either machine if he was having trouble with the synchronization. It was a clever device, but came a little too late in the 3-D cycle to make much difference. By that time, the damage had already been done. From our research, it seems that one of the primary reasons 3-D died so quickly was due to out-of-sync presentations. I talked with one service rep who worked for the Skouras theatre chain in New York. He was assigned the job of spot checking theatres that had 3-D shows. He told me it wasn't unusual to find films running two or three frames out of sync! This would cause havoc with your eyes, and give you a terrible headache. When Polaroid introduced these 2 sync control units in November of 1953, many people had seen so many poor 3-D presentations, it was hard to get them back to the theatres. If they had only developed these units 6 months earlier, 3-D would have probably lasted a lot longer!

By the way, I have a mint, never used copy of this sync control unit in the archive, but I have never been able to find the deluxe electronic version, which was model # 21. This was a much more expensive unit ($500.00, as opposed to $95.00), and was designed for the larger movie palaces. I would love to find one of these. If any one is working an older booth that goes back to the early fifties, keep your eyes open for me. I would pay a good price if this unit becomes available.

Thanks again for your letters. If anyone has any questions on 3-D films of the 1950's, just drop me a line.