Why 600EX II RT / ST-E3-RT Drops Wireless Link

[JLCKJC]

I am posting this information in hopes it is easier to find. It was originally a reply to an earlier post but may not be easily discovered.

I believe I have proven the theory that the Canon ST-E3-RT (ver. 2) / 600EX II RT wireless system is dropping wireless links because of external electromagnetic interference. As I mentioned in an earlier post I ran a number of tests yesterday with the ST-E3-RT sender and three 600EX II RT flashes, trying different channels and ID's. This testing was done in my home office not far from my Wi-Fi router. This home office has a single router and the normal complement of connected wireless devices (a couple of TVs, an Echo Show, one Samsung and one Apple cell phone). In this environment I experienced drops in less than a minute to at most 12 minutes. Some channel/ID combinations were better than others.

This morning I conducted a similar test on the same units. This time, I created a Faraday cage of sorts by placing all units (sender and Flashes) in a metal filing cabinet in my garage. This was in hopes of shielding them from most of whatever electromagnetic interference I have in my home office.

They ran flawlessly for over an hour before the flashes powered down as they were set to do. I then cycled the power on the remote, the three flashes woke up and reconnected and flashed when the test button was pressed. It's been over 30 minutes since the system was powered back up and still no drops. Each flash is in its own group; A, B, and C. A & B are in ETTL mode, and C is in manual mode at 1/128 power.

I believe this series of tests and the experiences that many of you have shared on this forum proves that the Canon flash system is unreliable where low to moderate electromagnetic interference exists. The system appears to be unsuitable for most venues in which it would likely be used where Wi-Fi and cell phones are in the vicinity.

This is an old design, but it's still being sold by Canon. The ST-E3-RT (ver. 2) was introduced a year or so ago and the EL1 & EL5, which use the same wireless protocol and have been reported to also have the same issues, were also introduced a little over a year ago. 

Now the question is, how do we get this information and test results in front of Canon so something might be done about this issue. At the very least they should stop selling this system until the problem is resolved in current production units. It's simply an unreliable system for real-world applications.

PS: As I post this note, it's now been 1 hour and 55 minutes, with no dropped links.

PPS: The flashes went through another auto power off as programmed and were again powered up when the ST-E3-RT was power cycled. Their wireless links restored as expected. I concluded the test after 3-1/2 hours with no dropped wireless links. I then removed the units from the Faraday cage (metal filing cabinet) and returned them to my office where they all lost their links in less than 5 minutes. Again, this points to external interference as the cause in a fairly common home Wi-Fi environment. This system appears not suited for its intended wireless use.

[rs-eos]

We don't have much home automation.  Just a few Apple Homepod minis.  Doesn't explain though why all the dropped signals in my back yard.

Hope you're able to figure out the root cause with your various experiments.

Still haven't experienced any drops with the Profoto gear.  So hopefully that is smooth sailing going forward.

[Nick55]

As I told the people at Canon CPS…. “Stop it with Optical as a solution.. what year is this?” Laughter in background….

[Nick55]

“Link Drop” started here at our one home here in the Philadelphia suburbs in January of 23. Tried every bit of trouble shooting. 5 600 Version 1 and 2 ST-E3 RT’s in any combination, Channel, ID, 1 600 -5 600’s, a 600 as Master…… Link Drop.

I sent into Canon CPS as directed to have firmware replaced in all units, only the Transmitters were updated and now noted as “Sender”….. “ Link Drop”

Put a Transmitter and 600 in microwave, yes microwave NOT turned on, and 2012-20-22 all over again. 
Contacted Canon CPS about why no update in Firmware on 600’s as situation was detailed. Also wanted me to ship to Costa Mesa for evaluation. I told them they were just sent in to VA. And came back. Told them that once others have sent theirs in and a solution I will then send my collection. Still waiting. 

[wq9nsc]

Ricky,

2.4 Ghz is one of the most populated parts of a very crowded RF spectrum.  Although WiFi is the best known, 2.4 also houses Bluetooth, many garage door openers, home weather stations, multiple varieties of home security devices, some car sensor arrays, and is also the spectrum center for microwave ovens which often leak RF over what should be a well decoupled power cord.  Some of the worst switching power supply designs produce garbage into the gigahertz range and the situation is going to continue to get worse.  ANY system using 2.4 Ghz has to be designed to be very robust against co-interference and de-sensing from overload and clearly the Canon flash system isn't.

Although it is more of a pain to set up, I use Hensel Expert D monolights which set up their own contained WiFi network and I have never run into an issue with them and that includes places where I have seen the Canon link system fail.  I have a couple of 600 series Speedlites but I never use them as a grouped light source since going with Hensel.

This isn't a good look for Canon, quality/reliability is my #1 requirement for photography gear.  All the performance, features, bells and whistles, etc. are meaningless if it doesn't perform with extreme reliability.

Rodger

[JLCKJC]

Can't agree with you more, this is not a good look for Canon especially since it's been a reported issue and growing for a few years now and even affects their most recently introduced flash system products. As with you, quality and reliability are top priorities for me, and this episode has shaken my 40-year loyalty to the Canon brand.

Flash photography is mysterious enough for many users; having to fight with your gear to keep it connected adds yet more uncertainty and doubt to the learning process. And for the professional, it makes you look like a dope in front of your customers as you run back and forth restarting your flashes and trigger.

There is no way I can recommend their flash system as it now stands to any photographer, professional or amateur.

[JLCKJC]

There is ample evidence that this is a real problem that so far Canon has not acknowledged or addressed in any way. Does anyone out there know how to break through to Canon Corporate to get this issue front and center with them. Maybe an X or TikTok exposé is needed because Canon does not seem to read or respond to the many posts about this problem in their own forum.

[Steppy]

If you still have your canon flash gear would you be prepared to turn off the Apple Minis and repeat the tests? I‘d be very interested in the results🙃

[rs-eos]

Sorry, I sold all of them a couple months ago.

[Steppy]

Hi Ricky

That’s good for you, so no reason to be sorry! Thanks anyway, Step

[pmsakamoto]

I actually tried the Westport trigger with my Canon flashes. I was able to get it to work, but just as you and I experienced with the STe3 it fails to hold the link longer than a few minutes. Another user did the same experiment and found the range was actually slightly worse using the Westcott FJ trigger running on the Canon RT protocol. When I switched the Westcott to run in Westcott’s proprietary mode with an FJ80m the link would stay live for hours. 

I repeated the experiment using a Godox trigger and Godox X1 receivers with my Canon 600EX. Once again, no problems. I was also able to see all the settings properly on the flash settings menu of my R6 Mk II on both the Westport and the Godox systems as they support ETTL as well as manual. 

im thinking this is purely a Canon issue and their implantation on 2.4GHz is not as robust as the others. Since it does work for a few minutes it may be mostly a lack of software to handle the spurious signals from other sources. 

I also tested this on a Canon EL5 flash using an STE10 trigger, it fails the same  way as all the other Canon radio links. 

I’ve been noticing that all the pros I’ve seen using Canon Soeedlites are direct mounting them on their hotshoes. Canon may not have enough complaints because of this?

it’s a disappointing mystery.