Use the Canon Macro Ring Flash
Macro flash rings are used for macro, or close-up, photography. Regular flash units produce shadows because they deliver the light from one direction. Ring flashes have a circular flash unit that produces shadowless images. Canon macro ring flashes have two parts. The control unit attaches to the camera's shoe-mount, usually found on the top of the camera body. The ring flash mounts on the camera lens. A cord connects the two parts and allows the camera to "talk" to the flash.
Instructions
1. Install four "AA" alkaline or nickel-hydride batteries in the control unit battery compartment. Magnesium batteries may also be used but they will not power as many flashes as the other battery types.
2. Loosen the locking collar on the control unit by turning it left to right. The locking collar looks like a wheel on the bottom of the control unit.
3. Slide the control unit's mounting foot all the way into the camera's hot shoe.
4. Tighten the locking collar right to left.
5. Attach the flash ring to the macro lens by pressing the release buttons on each side of the flash ring. Release the buttons to make sure the flash ring is attached to the lens.
6. Turn on the power to the control unit.
7. Allow the pilot lamp light on the back of the control unit to illuminate. Press the pilot lamp button to test-fire the flash.
8. Press the mode button on the control unit to select either E-TTL (automatic) or M (manual) flash. If E-TTL is chosen, set the camera mode dial to P (program, where the camera sets flash aperture and shutter speed) or AE (aperture priority, where photographer sets the camera's aperture and the camera sets the shutter speed).
9. Press the ratio button on the control unit to change the ratio between the left light bar and right light bar. Ratio on the top line should be highlighted. Press the left triangle button or the right triangle button to change the ratio. Available ratio ranges from 1:8 (the right tube will give off more light than the left) to 8:1.
10. Take the picture.
