600-EXRT /1 Dx2 flash assist infra red not working...

[George]

I may be having a senior moment re the above, but it seems the infra red pre flash unit is not functioning when I use the above set up...and it's not the body as I've swopped between mine

Custom function not set to off, trying in "p" mode with single shot af but no obvious pre flash.

I remember my 580 EX had a very visible IR pre flash, but the 600 hasn't.

Looked at all my CF functions etc, but no luck.

Any suggestions?...RTFM doesn't seem to work (and that was a last resort before the post!!)

George.

 

[George]

Well I seem to have stumbled on the answer quite by accident....I always use BBF and the shutter button is therefore actuating metering only, however as soon as I press the back button, the af mode changes from 1 shot to ai servo.

Now why this happens, I don't know, but I know that the pre flash only works in single shot mode (which I never use but I had altered for this test) so enabling the shutter button to do both focusing and metering solved the problem!!

Any suggestions why this BBF should change af mode as well?

George.

 

[Gaz J]

George.[/QUOTE]

Well I seem to have stumbled on the answer quite by accident....I always use BBF and the shutter button is therefore actuating metering only, however as soon as I press the back button, the af mode changes from 1 shot to ai servo.

Now why this happens, I don't know, but I know that the pre flash only works in single shot mode (which I never use but I had altered for this test) so enabling the shutter button to do both focusing and metering solved the problem!!

Any suggestions why this BBF should change af mode as well?

George.

Hi George

All I can think of is if you've got AI SERVO set for the back button in the custom controls and are changing it to one shot on the top LCD it doesn't override the custom control setting.

 

[George]

Thanks, Gary, I've only just realised that both of my bodies for some reason had that setting, I've now modified it to "Maintain current settings" so all I've to do now is to remember to set my af setting to "one shot" when I want to use pre flash!!

Cheers and a Happy Christmas to all!!

George.

 

[George]

A further comment..I suspect AI servo is the default rather than "maintain present settings"...worth a check as I don't remember altering mine!!

 

[Phil V]

Thanks, Gary, I've only just realised that both of my bodies for some reason had that setting, I've now modified it to "Maintain current settings" so all I've to do now is to remember to set my af setting to "one shot" when I want to use pre flash!!

Cheers and a Happy Christmas to all!!

George.

I have C1 set for flash work, M ISO 400 one shot AF 1/100 f5.6 (IIRC)

Which is very different to my defaults.

 

[George]

I use c1 and c2 all the time, but c3 is free so that's a good idea, Phil, might just adopt that!!

Thanks for the input and (almost) Happy New Year!!

George.

 

[Gaz J]

I'd forgotten about the C 1,2,3 custom function. Used to have them set when I had my 1DX but since they changed the custom controls on the MkII I've not found the need for them.