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Canon radio-controlled flashes failing in use - Senders and receivers disconnecting



I am spreading the news about the failure of communication between Canon "Sender" (Master) flashes and Canon "Receiver" (Slave) flashes.  Since around 2020 the communication between Master and Slave flashes can be broken by a public radio wave of some kind.  I’m not an EE, so I can’t tell you what the source of the problem is, but I can tell you that I have tested equipment all over the greater Seattle area, and about 80% of the time the Slaves disconnect from the Master in under 20 minutes of being turned on.   The shortest time to disconnect happens in 60 seconds with most disconnects occuring in 8-12 minutes.  I’ve only tested this in the greater Seattle area, but I suspect that if you are in a major urban area you will experience this failure.

I’ve tested this with Canon 600EX RTs and with a new R3, RL-5, and ST-E10, so it’s happening to the latest Canon equipment. 

You can read about what I’ve tested here:




Well, you could say that Canon should withdraw the offending devices from the market entirely, and take back those already sold and in user hands, and completely re-engineer their product to fix the problem....using different radio frequencies or however. Satellite engineers could do the same. And GPS system builders. And aviation altimeter designers.

Then we'd all be fine. Until 6G or 7g or 12G........

There are lots of examples of new technology allowing us to do wonderful things until it is discovered that the new technologies can conflict with each other. It can and will happen with other photo-related things.

I'm not providing answers to make you happy. That's way beyond my ability, and yours. 

The only quick answer for Canon flash users is to give up on wireless syncing. Change to another source, hoping it too doesn't fall prey to the Gs. Or go back to wired slaves and long extension cords, like studios do. 

Or Canon could just acknowledge the problem and let us know when they have a solution.  But continuing to sell a product that you know is highly likely to fail is simply wrong without a full disclosure before the sale.  I'm pissed, but I have 6 "old" 600s, if I had just purchased 6 EL-1 at $6,000+  I'd be livid.

Funny you mention studios... I have a very old technology wireless trigger system in my studio that works 100% of the time, whereas my Canon equipment fails 100% of the time at the same location.


I use Hensel Expert D (three 500 and one 1,000 watt unit) studio strobes along with a couple of their Integra series strobes and I have used them on location multiple times without a glitch including twice where Canon flashes were failing.  The Hensel units worked perfectly without drama including creating their own standalone WiFi network allowing adjustment of power output, modeling lights, test firing, etc. from the Hensel phone app.

I suspect the anger at Canon over this issue is because most of us have been Canon users for many years because of Canon's performance, product quality, and reliability which has been coupled with excellent customer service.  If these failures were occurring with a "Me Flash TOO" or some bizarre Amazon sourced brand then this level of irritation wouldn't exist.


EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video

Thanks for the info.  I know there are lots of solutions out here... however my point is that Canon is not responding or fixing the problem, which leads me to have to consider dumping all my Canon gear for another brand.  If they are unwilling to acknowledge the problem and take steps to fix the problem (not necessarily in old equipment), then they are out of touch with the community and I'm not sure I want to keep giving them money.  Problem is, that they are into me for $45K+ and for me starting over is a bit challenging.


I am feeling the same way. Canon keeps introducing new products using the same unusable Wi-Fi communications system. It does cause one to wonder how in touch they are with their customer's needs and concerns.


Canon is probably retreating, just like many manufacturers, childrens furniture, computers  (Apple, anyone?)....especially when they don't have answers or don't want to admit to liability, or don't want to take financial responsibility unless forced to by government, or lawsuits, or massive bad publicity

It's sad that our favorite photography company would be in this boat.

That's all I can say. I hope Canon flash users get some satisfaction. Could be years.


I get that on the "Old" equipment.  But for gosh sakes, to issue a brand new flash this year with the same problem points to a deeper problem, and given that many report using competitive brands without issue means it can't be that tough to figure out.


I just finished a photoshoot with my R5 and a Godox AD360ii-c flash with a Godox X3 Xnano trigger. I shot almost 700 flash images without a single issue. As a suggestion, you might try a Godox or Flashpoint trigger to see if that makes a difference. With my EL-1, I typically connect it to the R5 with a cable connector. As soon as I get a chance, I'll try using the X3 to wirelessly fire the EL-1 to see if it drops a link.


I have the exact same behavior and it's frustrating!  Suburban Denver with a wi-fi router (of course) and lots of wi-fi devices in the house (of course). 

Hey, Canon!  WHY doesn't the software initiate a re-link when it drops? 


I've been looking for a way to preserve some of my Canon flash investment while hoping that Canon will eventually come up with a possible fix for the Wi-Fi issues afflicting their system. After reading the posts of a few other beleaguered users I came upon a thread a few weeks ago that posed a possible but clumsy interim solution.

To try it out, I purchased a Godox X Pro II C trigger and three Godox X1RC receivers for my Canon R5 and my three 600EX II RTs. These Godox models have been specifically modified to work with the Canon system. The trigger goes on the camera of course and the flashes are mounted to the hot shoes of the Godox receivers and put into manual mode. Basically, you are in effect replacing the Canon wireless connection with the Godox connection which communicates between the camera and flashes and controls them in TTL or manual mode. The system also has the ability to transfer an ETTL/TTL exposure to a manual setting if you want to. You have 32 channels and groups A through F as well as user unique codes.

But most importantly, when I played with this system this afternoon where my Canon flashes failed miserably time after time losing the Wi-Fi connection over and over no matter the settings, the Godox system worked flawlessly. I know it's a kludge, but it works and gets me a workable system for about $210; $90 for the trigger, $40 for each receiver (3 in my case).

I hope this information is useful to one or more of you out there as we wait for a response from Canon. If Godox can design a reliable system, surely, you'd think Canon can too.