Speedlite 430EX III-RT AF assist beam won't work

[Flaherty]

I'm hoping someone can help.

I've just bought a Canon 430EX III-RT and for the most part I'm very impressed with this speedlight.  However, when I try to set up the AF-assist IR beam both on and off my camera (Canon 90D) it won't work.  I've gone into the sub-menu P.Fn 05 and selected "1".  When I back out, however, the icon shown is for the standard flash, not the specific AF-assist IR icon.  The red IR will not function.  I have no problems with the master-slave off-camera flash function which I think is great.

Has anyone else had this issue?  I hope it is just a set-up error on my part.  Every other function of this speedlight appears to function as required.

I don't do much flash photography but I never had this problem with my Canon 380EX which unfortunately gave up (finally) after 25 years of faithful service.

I look forward to any assistance provided.

Thank you.

[Anonymous]

For the IR assist to work, you can only use the center focus point. If any other focus points are selected, the IR doesn't work. See from the manual concerning P.Fn-05 setting of 1:

 

[Flaherty]

Hi Bob, thanks for the quick reply.  I actually found that suggestion in the long version manual but it has not helped.  For some reason I cannot get the icon on the flash LCD screen to show the AF IR icon. Beginning to think this is a problem with the unit.  I've only just bought it so it's under warranty.  Just so inconvenient to return it by mail (as that is how I purchased it).

[deebatman316]

With the camera set to the center AF Point or Auto AF Point selection and the speedlite's AF Assist Beam projection method set to IR. Does the speedlite project an IR Beam at all or no beam at all. Try this test in a dark room so you can see the IR AF Assist Beam. Does the speedlite trying using Intermittent Flash Firing.

 Limitations of the IR AF Assist Beam

[deebatman316]

The 430EX III-RT IR AF Assist Beam only works with the center AF point ONLY. If auto AF point selection or the center and another point is set. Then the IR AF Assist Beam is projected also. You don't need to set the camera to IR Only. The speedlite's personal function controls AF Assist Beam projection method. Setting the camera to IR AF Assist Beam only. With the speedlite set to Intermittent Flash Firing. Results in NO type of AF Assist Beam emission from the speedlite. Note that the IR AF Assist Beam is INCOMPATIBLE with EOS R series cameras. Intermittent Flash Firing is still used. Regardless of the AF Assist Beam projection method.

[Flaherty]

Hi Demetrius,

good advice regarding the EOS R cameras - as yet I don't own one.

Re. my flash unit, your advice and that of the other person who replied does not seem to have solved my issue.

For some reason I cannot get the icon on the flash LCD screen to show the AF IR icon. Beginning to think this is a problem with the unit.  I've only just bought it so it's under warranty.  Just so inconvenient to return it by mail (as that is how I purchased it).

F

[deebatman316]

Is any IR Beam projected at all from the speedlite. No IR Beam at all or Intermittent Flash Firing. Or NO AF Assist Beam projection AT ALL. When the camera is set to center point AF with IR set.

[Flaherty]

"Is any IR Beam projected at all from the speedlite. No IR Beam at all or Intermittent Flash Firing. Or NO AF Assist Beam projection AT ALL. When the camera is set to center point AF with IR set."

Nothing.

[deebatman316]

Is the camera set to AI Servo. The AF Assist Beam won't be projected then. Use One Shot or AI Focus. 

[Anonymous]

Are you trying the IR beam with the flash mounted on the camera or not? It will only function when mounted on the camera.

Also, are the in-camera flash settings set for IR firing? It can be disabled via the camera menu also.

Besides checking the icon on the flash, have you actually tried it on camera to see if it lights up red in the front of the flash with your lens cap on and pressing the shutter button?