Stafford wrote:
Using a Nikon SB-700 and SB-600 on a Nikon D7100. The speed light puts out 2 busts of light, and then the main blast. This all happens with 1 second from pushing the shutter. This happens with each of the speed lights, as well as when using a Yongnuo transmitter and receiver. I have used the flashes on another camera, D7000 and they work just fine. Does anyone have any suggestions as to what settings are wrong in my D7100?
A single burst of light is a normal preflash used to set exposure in TTL (Through The Lens) mode. The preflash and main flash are very close together, typically less than 1/20 second so you are not likely to notice it much.
There is a redeye-reduction mode on some cameras that produces a couple bursts of light before the preflash/main flash sequence. That causes people's pupils to contract, thereby reducing redeye. I don't have a D7100 so I don't know that it has that feature but read the fine manual and see if it's there.