Do Canons and Nikons have the same size hot shoe?
I'm getting a Nikon camera, but was originally planning on getting a Canon. The Nikon D3100 and the Canon Rebel T3 to be exact. Are the hot shoes on these brands/models the same size, so that I can get the same external flash I picked out for the other camera?
All cameras have the same ISO standard hot shoe but for Sony/Minolta proprietary hot shoes.
What is different are the special contacts used to control the dedicated flash units communication with the camera.
Nikon has what is called CLS (Creative Lighting System) and the Nikon SB 600 flash units and better can be used.
Here is a link to a full discussion of using the Commander Mode (CLS) including some lighting setups.
A canon Flash on a Nikon body will only work in manual mode so no TTL metering Same with Nikon on Canon. If you are looking at third party flashes like Sigma or Yungnuo it's the same thing, they have Canon and Nikon versions of their flashes.