R6 not focussing when using strobe light - red square appears when pressing the focus button

[mojito]

Why, why, why? Will the R6 not focus? I always get the red square when I focus on the eyes - and not the green. And yet when I switch to manual AF it's focusses fine.

Settings are:

ISO: 200
Shutter: 160
Aperture: 7.1
Lens: EOS 70-200mm
Focal Length: 85mm

HELP!

[Tronhard]

If this happens when using the strobe have you checked that focus assist is enabled for flas photography?

[mojito]

Oh no, I didn't even know about that function.
Will look it up and check my camera setting (in the morning :))

Thank you so much. I will update on the morrow. 

Best,

Josie

[mojito]

Sorry -  I might not have made myself clear. Why won't it focus on AF? 

The focus assist works only for the Manual focus setting - is that right? Which by the way, it does when I set the camera to manual focus. Works great. 
But I want to auto focus using the strobe.

[Tronhard]

What kind of flash unit are you using?

If you look on P153 of the user manual, is says "the Speedlite will automatically fire a focus assist beam as needed, if autofocusing is difficult under low light".   Thus this should work: if it doesn't check your Speedlite settings and if necessary refer to its documentation.  If it is not a Canon Speedlite, definitely refer to the flash maker's documentation.

[mojito]

Thanks!
I'm using the Godox 400AD Pro. Have just done a quick search and there doesn't seem to be a focus assist beam with this model/brand? 

You're right, I think it's a low light thing. Frustrating. I'm not sure why all of a sudden it won't auto focus when it has operated in similar set up, before.

[Tronhard]

If it DID work on this camera before, perhaps do a camera reset and see if some unknown setting has changed the situation?

[mojito]

Thanks, Trevor.
Yes, will try that. Was trying to avoid resetting so that I don't lose my awesome presets - but the pain of not having autofocus is far greater. 
Will see how it goes...

[Tronhard]

save your current settings to one of C1-c3 modes, before you do a reset?

[mojito]

omg - YES! Thanks. Heaps. (NZ slang)