Showing results for 
Show  only  | Search instead for 
Did you mean: 

Radio communication issues.EL-1, 600EXII-RT, 430EXIII-RT, YN686EX-RT, ST-E3-RT Speedlite Transmitter


Hello, Canon. Hi everyone, I've been a professional wedding and event photographer for 25 years, and in the last two years. I have used around six off-camera flash techniques using the six flashes mentioned above. After hundreds of weddings in the previous month, I have connection-linking issues. I read and checked every tutorial possible, and nothing helped.:( I know the menu's sub menus' custom settings, and the only flash linked for hours is the Yonguno YN686EX-RT. All of my Canon brands flash, losing connection after 5-minute. I attached two cellphone photos where you can see the problems after 5-minute. CANON or some of you guys have any idea what's going on? PLEASE HELP ME! Thank you so much. 




Hazel, please check this out; here is my website I am a professional photographer from 25 years.


I’ve been having the same issue since switching over from my 5D Mark II. With that body I used the ST-E3-RT, 135MM, 85MM, and 35MM prime EF L lenses. No issues at all. Once I switched over to the Canon R body started using 14-35MM RF lens and my original ST-E3-RT, the drop link issue started. 

I’ve also followed the suggestions (specific channel, ids, etc…) but issue still persists. 

I did also notice that I did get improved performance when I disabled both Bluetooth and WiFi settings on the R body. My thought is the issue is related to some type of interference (as suggested above) since I didn’t have this with my old 5D Mark II body. 

One more test I’m going to do is take this outdoors away from any WIFI. 

Wow, this is exactly me! How disheartening. Thank you for the tip on disabling bluetooth/wifi, since this always happens for me indoors. I will try to see if that helps any.

I just shipped off my R6, new flashes, transmitters, and lens to Canon to have them look at it. They said everything was fine - so that is a huge disappointment. It must be interference. 

What a huge disappointment, Canon! Can you please help all of us???

-Moving reply to the correct thread

I did a test outside. Not sure what was around but assuming there was less RF interference, the setup worked with no issues. In fact it seemed to fire off faster with no delay. Given I have mesh wifi setup at  home,  I think this  is the source of my issues. 

Hi, everyone; I was tired of struggling with Cannon flash problems and other autofocus issues, and I switched to Sony a7r5. We are hybrid media creators. For us, it's essential to be able to create professional-level photos and videos too. We now have four Sony cameras and five premium lenses with a Flashpoint flash system. They are not perfect, but 98% yes. 


I have the same exact issue. ST-E3-RT with any combination of one 600EX-RT and two 430EX III-RT. I also tried 600EX-RT as master and 430EX III-RT as slave. Connection is lost in few minutes and only power cycle can help. I tried an R5 and a 5D mark iV. Same result. Turned off all wifi in the house. Same result. Is Canon going to explain what is going on?

I'm so sorry you're dealing with this too! Two days ago I just tried turning off WiFi at home to see if that was my issue - and it didn't help. I have thousands of dollars worth of flashes that are worthless to me if they mess up at sessions. It gives me so much anxiety going into every single job. 

I find it very unlikely that this is wifi interference. I can't believe that a wifi interferer is so strong that it affects a link when the transmitter and receiver are sitting right next to eachother, I'm also surprised that canon is not all over this already. Seems like a huge issue that will push customer to other brands very very fast.

I'm currently trying the approach of using a Godox transmitter (XProC-$69) in my camera hot shoe with Godox receivers (X1R-C-$40) attached to each of my Canon (600EX-RT) flashes. My first shoot using these will be over the weekend.   In my experiments, so far, so good.  Easy to set up groups and channels. The flashes are behaving - haven't lost connection (longest "sleep" test I tried was 20 min). Easy to see & change power levels of each group on the transmitter.   Does Godox use the same 2.4GHz spectrum as Canon? Yes; however, it seems that they do a better job maintaining that communication (according to what I've read, the folks I've talked to, and what I've personally seen so far). 

(When I first started doing a lot of inquires, it seemed that the two names I keep hearing was Westcott and Godox.  I initially went with a Westcott transmitter (as the cheapest solution)  but after reading about others' experiences with that (that system really needs Westcott flashes for the increased reliability), I jumped over to pursuing the Godox solution)

Thank you so much for all the detailed information! I will have to look into this myself too! I've never tried Godox - and it's such a shame that our Canon flashes (which are all so expensive) aren't working for us. Does anyone have ideas of how we can sign a petition, or somehow light a fire under Canon to get Canon working on a fix for flashes?!