Reset C.Fn-5 is set to 0 (E-TTL).

Article ID: ART129186 | Date published: 05/12/2015 | Date last updated: 08/17/2015


Reset C.Fn-5 is set to 0 (E-TTL).


You can customize the Speedlite features to suit your shooting preferences. You do this with Custom Functions.

How to set Custom Functions

Hold down the button until C.Fn is displayed
Select the Custom Function Number
  • Turn the dial to set the Custom Function Number

Change the setting

  • Press the button
  • The Custom Function Number blinks
  • Turn the dial to set the desired number, then press the button
  • After you set the Custom Function and press the <MODE> button, the camera will be read to shoot

Special Notes

C.Fn -02-3: Convenient when you want to check the depth of field

C.Fn -05-1: Is for use with EOS-series film cameras. Do not set it if you have an EOS Digital camera or the EOS Rebel T2/300X. If this custom function is set with such cameras, the flash control will not work properly. The flash might not fire or it might fire only at full output.

  • With Type-A cameras, if C.Fn-05-1 is set, wireless autoflash shooting will not be possible
  • If "AF-assist beam OFF" is set with the Speedlite or camera, the AF-assist beam will not be emitted.
  • With Type-B cameras, even if C.Fn-05-0 is set, E-TTL II/E-TTL autoflash will not work

C.Fn -12 : If an external power source is used, the flash recycling is powered concurrently by the batteries and the external power source. In this case, when the batteries become exhausted first, shooting might not be possible. If 1 is set, the flash recycling will be powered only by the external power source. The batteries will therefore last longer. Note that even if you set it to 1, the Speedlite will still require batteries for flash control.



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