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]

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. 

[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]

Please keep us posted on your experiments. Given the tests and comments done and made recently there is no doubt that Wi-Fi interference is the most likely culprit. The amount of Wi-Fi pollution continues to grow as time passes and more and more devices are introduced that use the 2.4GHz frequency range. This would explain why the Canon system was reliable in the past but now is not. Even though the STE-E3-RT and the 600EX-II-RT models have been discontinued Canon recently released and continues to sell new, and more expensive models using the same communication protocol which are reported to have the same issues. So, you would think Canon has a continuing interested in solving this issue. Now the key is how do we get this information to Canon.

I was able to talk with two Canon technicians in the Canon service organization who were sensitive to this issue. I was told my findings would be passed on to Engineering for consideration, but I have no idea if that will really happen in reality. Does anyone have access to the Canon Photographic technical community or know how to contact them? If so, please chime in so we can be sure this issue is communicated to them. This is a real issue that needs to be resolved.

[pmsakamoto]

My latest experiments:

1. Westcott FJ-X3m universal flash controller and a Westcott FJ-80ii Speedlite. 
   1. Worked reliably in the environment that took out the Canon wireless in a couple minutes. This combo also woke up from sleep mode as well. 
   2. Worked fine with my R6 MkII. This said, I didn’t care for the way it worked through “flash settings” on my camera. It is much easier to use the controller. Also, although some folks love the touch panel setup and high visibility of the current settings on the large display on the flash, I found it unfamiliar and cumbersome to make setting changes. That said, clearly a viable option that allows compatible capacity upgrades through their FJ line (200w, 400w, portables).
2. Godox XPro II TTL flash trigger for Canon and a Godox X1RC receiver. The XPro goes on the camera hot shoe and the receiver attaches to the hot shoe of the flash. 
   1. This duplicates an experiment others have done.
   2. I ran multiple flashes this way in the hostile environment for over an hour and had zero issues with the link or with wake up.
   3. I personally like the way the Godox interfaces with the camera better than the Westcott, although the Westcott clearly has the edge in documentation and service. This has also been documented by others.
3. Note that Westcott, Canon and Godox are all running on the 2.4GHz band, but only the Canon wireless protocol, whether on Canon hardware or Westcott, is unreliable as we’ve all noted. This means that either they are:
   1. Not exactly using the same central carrier frequency, 
      1. I doubt this because even if they are off by a hundred MHz, it would be surprising to have it remove the interference since 2.4GHz in general has become broadly polluted with all sorts of random signals. Move below 2GHz and you start to run into some types of Cellular. Move too high above and you run into other licensed band.
         1. That said, I have acquired a spectrum analyzer and will check this out. 
   2. Have different data protocols with different error tolerance and recovery.
      1. Likely a factor, but hard to tell without the three companies discussing it.
   3. Use different semiconductor radios that have different performance. 
      1. Possibility since it’s likely Canon reused their old chips and the others used the latest chips since they were developed later. 

I’m still surprised Canon is not seeing this as an issue to be addressed. 

[JLCKJC]

Thanks for doing this additional and interesting testing on the Westcott and Godox models. Your results continue to point to an issue specific to the Canon system and protocol. In an earlier report you tested a Canon flash with a Westcott controller and reported that this combination was unreliable. Can you test a mix of Canon and Westcott flashes with the Westcott controller and if so, determine if the Canon flash still fails while the Westcott does not? I think this might provide some additional clues as to what might be going on here.

[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. 

[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.