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.
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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:
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2. Press the <-> button to select RATIO ON A:B
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3. Press the <SEL/SET> button again to select RATIO ON A:B C
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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
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8. Press the <SET/SEL> button again
- RATIO C and the flash exposure compensation display will blink
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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
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- 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.