ETTL: Wireless Multiple-Flash Photography with Flash Ratio

Autoflash with Two Receiver Groups

You can adjust the lighting balance (flash ratio) with receivers separated into 2 groups, A and B.

The total (sum) of light from firing groups A and B is automatically controlled to a achieve standard exposure.

1. Set the firing group of the receivers.

   • Set this manually on each receiver.
   • Set 1 receiver to and the other to .
   • For instructions on configuring receiver settings, refer to the instruction manual of the flash unit.

2. Select [Flash group].

   
   • Complete steps 2–4 using the sender.

3. Set to [A:B].

   
   • Select [A:B] and then [OK].

4. Set the A:B flash ratio.

   
   
   • Set the A:B flash ratio, then select [OK].

5. Take the picture.

   • The receiver will fire at the set flash ratio.

Autoflash with Three Receiver Groups

Once flash groups A and B have been set up, you can add group C to fire with multiple flash units. For an overview of flash control, see “Group Control.”

C is useful when you want lighting that eliminates the subject's background shadow.

1. Set a flash unit as firing group C.

   • For instructions on configuring receiver settings, refer to the instruction manual of the flash unit.

2. Select [Flash group].

   

3. Set to [A:B C].

   
   • Select [A:B C] and then [OK].

4. Set the A:B flash ratio.

   
   
   • Set the A:B flash ratio, then select [OK].

5. Set the flash exposure compensation amount for firing group C.

   
   
   • After setting the compensation amount, select [OK].

6. Take the picture.

   • Just as in normal flash photography, shoot after configuring the camera.

Group Control

Firing group A

You can add more receivers when more light or sophisticated lighting is needed. For added receivers, simply specify the flash group (A, B, or C) that you want to be brighter. Up to 15 receivers are supported.

For example, when three receivers are set to flash group , they are all controlled as a single, high-output flash unit in group A.