Now by no means am I a camera flash expert, so the following is just what I’ve observed in the last little bit messing around with my new Canon 7D and it’s wireless flash controller feature.
I’ve been wanting to take my photography to a new level and one way I thought about doing it was the use of a flash. I don’t mean that wimpy pop-up flash that all dSLR cameras have, or that built-in flash that many compact digital cameras have. I’m talking about the larger, external hot-shoe flashes, such as the Sigma EF-530 DG Super flash I own.
One interesting feature of the Canon 7D is the ability to be used to trigger remote flashes. How does it do this? It uses the pop-up flash to send out pulses to remote flashes that are acting as slaves in order to trigger them. Or so it seems to be explained in the manual that came with my Canon 7D.
As for what I did was relatively simple. I set the Sigma flash to E-TTL mode as a Slave and kept it on Channel 1. In the Flash Control option on the Canon 7D I set up the built-in flash to only trigger the remote flashes and not the pop-up flash as well. The pop-up flash will send out a low-powered flash pulse to the remote flash which sends the settings it needs for the shot milliseconds before the remote flash goes off. The pop-up pulse flash typically has no bearing on the final result of the photograph, or so I’ve read.
I attached the Sigma flash on my tripod a few feet in front of me and turned the optical sensor to face my camera, and turned the flash head towards my subjects. While in the Flash Control menu option, you can fire a test pulse which will trigger the remote flash to ensure the two are talking properly.
The Subjects and Results:
I experimented with various settings on my Canon 7D to get a better feeling for the use of a flash. I switched between Tv and Av mode, I dialed down the exposure on the camera, I dialed down the flash exposure on the Sigma remote flash itself. I moved the flash around in various positions.
So far I am really liking the ability to trigger remote flashes. According to the manual, I can remotely trigger at least 3 remote flashes in a 80 degree field of view from the pop-up flash that are roughly 7 metres (24 feet) away. Depending on the flashes use, the subject could be up to 10 metres (32.8 feet) away! Not bad, though for anything of decent length away it would most likely be better to trigger the remotes via a dedicated wireless system such as PocketWizards or AlienBee’s CyberSyncs. For now though, I am going to have fun messing around with this.
Who knows what I will do next! But I am sure having fun, just hope my batteries in my flash a bit longer. They are rated for 200 flashes (normal power) with 4x Alkaline batteries. Only 100 flashes if I use NiMH rechargeables.