cancel
Showing results for 
Search instead for 
Did you mean: 

AF assist beam with external flash and 80D

Tubeydude
Apprentice

Hi all, I'm new here, but have had my 80D for about 5 years and really enjoy it.  I was trying to do some low light pics and used my external flash rotated to the side to get some softer fill light.  It was having trouble focusing in low light (not too surprising)  I usually just switch to manual focus when I have this issue, but as the subject was moving a bit, I though I would try turning on the AF assist bean that my flash has and see if that would help me out.  ( flash is a Godox TT685, which has also been great.)

I found that the AF assist beam on the external flash only fires when I am using the regular viewfinder, and when doing so, it greatly speeds up autofocus, as one would expect. However, If I go to live view shooting, the AF assist beam does not fire and the camera hunts for focus.

Is there a reason why the AF assist beam on the external flash would not fire when in live view shooting?  It seems to do this regardless of the shooting mode I'm in, P, Av, Tv etc...

I have the camera AF setting to live view plus tracking.  AF assist beam is enabled and red eye reduction is disabled? 

Thanks!

4 REPLIES 4

kvbarkley
VIP

Because the sensor is not sensitive to IR light because of the IR filter. It requires the phase detect chip that is active when using the viewfinder.

Tubeydude
Apprentice

Thanks!  That would explain it.  I guess the IR filter must be directly over the imaging sensor...

I wish there was a way to make the AF work better in lower light.  It looks like there is plenty of contrast on the live view screen, but it still hunts for focus, going right through it often.  I tried messing with some of the custom function settings, but didn't really see much improvement.

Newer cameras, like the R series, have phase detect areas on the sensor. I don't think the 80D has that.

deebatman316
Contributor

The Canon 320EX speedlite uses an LED light for an AF Assist Beam during live view shooting. When using the viewfinder the speedlite will pulse rapidly (intermittent flash firing method) to provide an AF Assist Beam during viewfinder shooting.

Announcements

08/09/2022: New firmware version 1.2.0 is available for CR-N 300
08/09/2022: New firmware version 1.2.0 is available for CR-N 500
07/28/2022: New firmware version 1.2.1 is available for EOS-R3
07/21/2022: New firmware version 1.6.0 is available for EOS-R5
07/21/2022: New firmware version 1.6.0 is available for EOS-R6
07/21/2022: New firmware version 1.1.0 is available for EOS-R7
07/21/2022: New firmware version 1.1.0 is available for EOS-R10
07/14/2022: New firmware version 1.0.1 is available for CR-X300
07/01/2022: New firmware version 1.3.0 is available for PowerShot PICK
06/30/2022: Service Notice: EOS 70D: Error 70 or Error 80
06/10/2022: Service Notice:UPDATE: Canon Inkjet Printer continuous reboot loop or powering down
06/07/2022: New firmware version 1.3.2 is available for PowerShot G7 X Mark III
06/07/2022: New firmware version 1.0.3 is available for EOS M50 Mark II
05/31/2022: Did someone SAY Badges?
05/26/2022: New firmware version 1.0.5.1 is available for EOS-C500 Mark II
05/26/2022: New firmware version 1.0.3.1 is available for EOS-C300 Mark III
05/10/2022: Keep your Canon gear in optimal condition with a Canon Maintenance Service
05/05/2022: We are excited to announce that we have refreshed the ranking scale within the community!
04/26/2022: New firmware version 1.0.1.1 is available for EOS R5 C
03/23/2022: New firmware version 1.0.3.1 is available for EOS-C70
02/09/2022: Share Your Photos is back!
02/07/2022: New firmware version 1.6.1 is available for EOS-1DX Mark III
01/19/2022: READY FOR ANYTHING EOS-R5 C
01/13/2022: Community Update. We will be retiring the legacy profile avatars on 01/20/2022. Click this link to read more.
01/05/2022: Welcome to CES 2022!
12/7/2021: New firmware version 1.3.0 is available for Mount Adapter EF-EOS R 0.71x