This is a very basic two strobe set-up. On my Canon 5D MKII, I mounted a 550EX + FLEX TT5 on camera to illuminate the subject and a 430EX II + FLEX TT5 on a light stand on camera left to illuminate the background. Both strobes were set to ETTL. The built-in wide angle flash diffuser on the 430EX II was extended to provide wider spread of the light across the background (which is a light colored painted sheetrock wall).

Canon's ETTL flash system is designed to automatically deliver the "right" amount of light to give a good exposure. To provide user control over this "right" amount of light, Canon Speedlights offer the ability to adjust the flash output through the use of Flash Exposure Compensation (FEC). Canon Speedlights can be adjusted in 1/3 stop increments to increase or decrease the intensity of the flash output over a six stop range (from -3 to +3).

The FLEX TT5 is one component of the CONTROL TL radio-frequency strobe controllers from PocketWizard. These units have tremendous range and offer a number of advantages over using Canon's own wireless control, which uses infrared technology to transmit wireless transmissions to control the strobes. Go to the PocketWizard website to see all of the advantages of using the Control TL system.

In this simple primer, I want to show what happens when you make adjustments to the FEC for the background and subject. Look at the caption for each image to see the notes on FEC settings. In all of these images, the camera is in MANUAL exposure mode, shutter speed 1/125 seconds, aperture f8, ISO 400. Lens is EF 24-70 f2.8L.

The subject (bust of Mozart) was placed on a stool about 5 feet from the wall. The camera was mounted on a tripod. The shutter was released using a remote release cable.