Setting the Flash Ratio for Three receivers Units: A, B and C

With three wireless receiver units, receiver unit A is the main flash, receiver B is the fill flash and receiver unit C is a supplemental flash. Thus, receiver units A and B serve to illuminate the subject for a proper exposure while receiver unit C illuminates the background to eliminate shadows. Even with three receiver units, the E-TTL autoflash system controls the flash to obtain a correct exposure.

In addition to setting the A:B flash ratio, a flash ratio of (A:B):C can also be set. This is done by adjusting receiver unit C's flash exposure compensation amount.

The following wireless E-TTL autoflash procedure is for a sender unit with three receivers units. This procedure sets the A:B flash ratio and the flash exposure compensation amount for receiver unit C

• The flash ratio range for A:B is the same as when only two receiver units are used
• Flash exposure compensation with receiver unit C can be set up to +/- 3 stops in 1/3 or 1/2 stop increments
• The receiver ID of the receiver unit on the camera's left is A
• The receiver ID of the receiver unit on the camera's right is B
• The receiver ID of the receiver unit illuminating the background is C
• sender flash OFF is set for the sender unit
• The camera (attached with the sender unit) and three receiver units are properly position for the subject.

	1. On the sender unit, press the <SEL/SET> button and select <RATIO> Pressing the <SEL/SET> button changes the selection in the following loop:
	2. Press the <-> button to select RATIO ON A:B RATIO ON A:B will blink
	3. Press the <SEL/SET> button again to select RATIO ON A:B C RATIO A:B C will blink
	4 . Press the <SEL/SET> button Ratio A:B and ? (flash ratio bar) will blink 5. Press the <+> or <-> button to set the A:B flash ration Press the <+> button to move the flash ratio bar to the left or press the <-> button to move it to the right on the flash ratio scale 6. Press the <SEL/SET> button The flash ratio bar and the RATIO A:B:C remains displayed 7. Press the <SEL/SET> button again The ? (flash ratio bar) for A:B will blink To change the flash ratio, repeat steps 4 to 6
	8. Press the <SET/SEL> button again RATIO C and the flash exposure compensation display will blink
	9. Press <+> or <-> button to set the flash exposure compensation amount for C
	10. Press the <SEL/SET> button to register the setting The flash ratio bar and RATIO A:B:C remain displayed To Change the flash exposure compensation amount, repeat steps 8 to 10

• Even if you have receiver units A, B and C if only RATIO A:B is selected, receiver unit C will not fire
• If receiver unit C is used to illuminate the subject directly, overexposure may result.