I covered some adventure races late last year, and I experimented with using ETTL infra-Red flashes. I wanted to get the main flash off-camera to give a deeper light affect on the subject.
Here’s an extreme example…..
The flash off to camera left is the main light source with the on-camera (on flash bracket – on-camera) flash is acting more as fill. This type of light gives the subject more depth and makes them look more natural.
So what’s the benefit of this in reality…… Well I found the greatest aid was speed in the field. You’re not shooting in a studio with a fixed subject and hours of time. you have 40 seconds to get your shot. With ETTL the remote flashes are already set.
All you need to do is place the remote flash, rotate the flash head so the IR sensor is pointing at the camera (to receive the ETTL Signals) and the head is pointing at the subject. The shoot away.
So Here are the settings :
Main Flash (On Camera)- you can have this flash on the camera’s hot shoe, but I like to have it on a flash bracket and use an OC-E3 ETTL cable. I’ll explain why later. I set this flash to Master and to channel A. Read the manual for how to do this bit. On the Main Flash you can set the ratios of A:B, i.e. A is 2 x as bright as B or vice-versa. The fact that you have this control on-camera (or on-flash) saves a load of time.
2nd/3rd flashes – I generally use 1, but you can use 2 or more to increase the flash intensity. Set these to Slave and to channel B. Make sure they are in the line-of-site of the IR transmitter of the Main Flash….more later.
So what are the problems; Basically to need to have the flashes in line-of-site of one another. If they can’t “see” each other, they can’t send ETTL flash info. This is why I use a flash bracket. This way I can move the MAIN flash around so the head is pointed at the subject and the IR transmitter is pointed to the remote flashes. It’s the same with the remote flashes. The IR receiver and the head may be pointing in different directions to work.
I have found this method fast, accurate and controllable when in the field. To have all the flash setting under your fingers is a great asset. Go and give it a go…..