Friday, December 28, 2012

The Taming of the Shoe

The PC Sync connector
Also in this issue:
  • A99's Wireless Flash Delay
  • A Zeiss Full-Frame Alternative
  • Seminar Update

The Taming of the Shoe

Once upon a time there were cold shoes.  Nobody called them that, but that’s what they were -- small brackets mounted onto the camera body onto which you could mount your flashbulb holder.

The original Flash bracket holder,
retroactively labeled the "cold shoe".
Once mounted, you would connect the flashbulb holder electronically to the camera via a PC Sync cord into a PC Sync socket (whose design hasn't changed much over the last century).  Inside the camera there was a mechanical switch which briefly “shorted together” the 2 wires of the PC Sync cable when the shutter was actuated.  It was a very simple and very effective mechanism, which also worked well when the electronic flash was invented.

Adding the circuitry to trigger the flash
now made it a "hot shoe".
“Hey, let’s get rid of that annoying PC Sync cable!” one engineer must have said to himself in the 1960’s, as he