Monday, 13 June 2011
Experimenting with Flash
The photo above was lit with a Canon 580EX-II hot-shoe flash. Not in the hot shoe of course, that would turn what is a fairly expensive flash into something no better than what most cameras have built in. A little bigger maybe, but no better.
I almost always shoot with off-camera flash like this.
So what is different in this shot?
Well, usually I treat my hot-shoe flash just like my studio strobes. Dumb sources of light which I have to set up manually using a light meter to test the strength of light. Until not so long ago this was the only way to shoot with flash and it is still very popular. If you are used to working in a studio then the way you work there translates directly to working with these smaller flashes. Best of all, you can buy cheap wireless (or even cheaper wired) triggers to make the flash fire when you hit the shutter release on your camera.
But these flashes, when paired with a good camera, are capable of so much more.
Using a series of pre-flashes the camera (a 50D in this case) and flash between them can work out the right settings to correctly expose a shot. Correct, that is, as defined by the designers of the camera. Since they don't know exactly what you are trying to achieve they give you some control through the Flash Exposure Compensation controls to adjust the results to what you want (within limits).
The benefit of this is speed. Manually adjusting lights and measuring with a light meter takes time, letting the camera work it out and then making adjustments through the camera is a lot quicker. Perfect when you have only a short time to get the shot or when you need to make several different shots quickly.