580exII on a 5DSR

[BrianAE1]

I used to use my 580exII on my 5DmkII for events and the flash would send out a red focus assist beam. It helped immensely when working events at night.

It doesn't seem to do that when I use it on my 5DSR and I just can't seem to get good focus in low light.

Is there a setting that needs to be changed? or is it not compatible with the 580exII? or is my flash not working correctly?

Thanks!

-Brian

[MikeSowsun · Accepted solution]

The red focus assist light only works in "One Shot" AF. Check and see if you are in AI Servo AF mode. 

[BrianAE1]

Ahh ok, yes I'm almost always in AI servo mode. I'll have to give that a try. thanks!

[BrianAE1]

Hi Mike,

That was the issue. thanks for helping.