# EOS M with 600RT assist beam.



## Daniel Flather (Jul 12, 2013)

How do I get the M to fire the 600's AF assist lamp? I turn the AF beam on/off that controls the M's beam and no go. I set the CF to turn on the AF beam and no go. I've even RTFM and no go. Will the 600's AF beam fire for the M, cuz in low light it needs it. 

Great camera BTW.


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## Swphoto (Jul 12, 2013)

The beam doesn't work when using Live View/contrast detect AF on other bodies (works on the 5D3 in Live View only with AF set to "Quick"). I guess that it won't work on the M since it's always using contrast detect AF.


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## Daniel Flather (Jul 12, 2013)

Swphoto said:


> The beam doesn't work when using Live View/contrast detect AF on other bodies (works on the 5D3 in Live View only with AF set to "Quick"). I guess that it won't work on the M since it's always using contrast detect AF.



Thanks. The only other thing with the M that is missing is the small raw file option. Maybe that can be added in a future FW update?


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## AudioGlenn (Jul 12, 2013)

hmmm... My M fires the AF assist beam with my 430 ex II attached. I had no idea my 600 ex-rt wouldn't work


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## Swphoto (Jul 12, 2013)

AudioGlenn said:


> hmmm... My M fires the AF assist beam with my 430 ex II attached. I had no idea my 600 ex-rt wouldn't work



It fires the assist beam on the camera body, or the speedlite's beam? I just tested with my 430 II and it behaves like the 600 - no speedlite assist beam on the M. The camera's beam will fire.

I disabled the M's AF assist beam, though. I'll enable it if I'm shooting in really dark conditions, but in more typical situations it didn't seem to help the AF speed.


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## AudioGlenn (Aug 3, 2013)

Swphoto said:


> AudioGlenn said:
> 
> 
> > hmmm... My M fires the AF assist beam with my 430 ex II attached. I had no idea my 600 ex-rt wouldn't work
> ...



you're absolutely right. my speed lights are not firing an AF assist beam. It's coming from the EOS M body.


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