Canon Community Canon Community

Occasional Contributor
Posts: 6
Registered: ‎04-14-2018

Re: 430EX III Buzzing when flashing.

I’m using Aperture Priority & Manual at times.

I went ahead and called Canon Tech Support and the representative was able to watch my video. The tech put me on hold while he grabbed my exact kit and lens so that he could see the problem, he guided me step by step but nothing helped even after resetting the settings on both my camera and flash. The tech suggested to send the flash for repair as it may be defected and warned me that the worse case scenario is that I would have to send my camera too as it may have bad contact with the hot shoe.

Instead of sending out my equipment I drove to my nearest Best Buy and tried my flash on several cameras like the 70D 5D Mark IV and 80D and to my surprise they all made my flash buzz which then clarified that it isn’t my camera. I asked the Best Buy rep if I could test the flash that he has on displayed and he accepted. The flash that was on display made the same buzzing sound and the same “pre-flash” as mine which put me at ease and maybe think that maybe that’s how it’s suppose to be.

I don’t know if this brings up further questions but it’s just very odd that no one has encountered this but me.
Reputable Contributor
Posts: 869
Registered: ‎12-24-2013

Re: 430EX III Buzzing when flashing.

[ Edited ]

I went through the 430EX III RT manual and discovered that focus assist is set up VERY differently on this flash.


The 270EX II, 320EX and now the 430EX III RT, are the only Canon external flash units that use a "series of small flashes" to aid in focus assist as a default function. Prior to these flash units, only the built-in flash units used this method. 


SO.... What you are seeing, and hearing, is indeed normal. I am surprised the Canon reps that you spoke to did not know this. 


The 430EX III RT is unique because a “Personal Function” can be used to switch to InfraRed focus assist. But, it is a smaller than normal pattern, and only works with the center AF point. 


You also have the option to disable focus assist. 






Mike Sowsun
S110, SL1, 80D, 5D Mk III
powered by Lithium

LIKE US on Facebook FOLLOW US on Twitter WATCH US on YouTube CONNECT WITH US on Linkedin WATCH US on Vimeo FOLLOW US on Instagram SHOP CANON at the Canon Online Store
© Canon U.S.A., Inc.   |    Terms of Use   |    Privacy Statement