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600 EX II-RT's dropping signal

jennybug678
Contributor

Hello, 

We are wedding photographers who have used Canon 600EX II- RT's for years now. We use them for receptions and lighting the dance floor, speeches, and creative shots. We have never had issues with connectivity until around 2019/2020. All the sudden since, it has been getting worse and happening at more and more venues. We have found our flashes will not stay connected via radio transmitters at certain venues. We do channel searches, place our flashes in different areas, etc, same issue. We will connect for 2 min, then it will disconnect out of no where. We use mainly another 600 EX II RT as the trigger (master) and other 600 EX II RT as slaves. We honestly are sick of it and are thinking of ditching Canon. We haven't heard of any other flash brands having any issues. Only hesitancy we have is that we have already 8 of these purchased from years of buying them and don't want to have to replace them all with a different brand. Has Canon came up with a fix for this or bettering their flash products? I see this is a known issue and it seems the only "solution" is use Line of Sight. Which won't work for how we use them most the time. ANY HELP PLEASE?

30 REPLIES 30

Shooting “Optical” is like shooting film. 
With line of site eliminated with Radio and 600 in Apollo Softbox for example, it would be like the Dark Ages as in 2011 and prior. 
Optical is not the solution. 

agreed, that is a cop out.

Agreed 1000%. I feel like Canon needs to change the technology to fix it. 

Not a good solution. Especially when I am shooting dance floor and reception events with these.

I wish! It really makes us mad too. We never had issues until a couple years ago.

chrishoesel
Enthusiast

I had the same issue 2 weeks ago shooting a friend's prom event at his house.  I was losing connection to my 2 600EX-II-RT's (using the ST-3-RT ver.2) every 10-15 seconds.  I did a channel scan and it showed several non-contested channels. (Channel 5, 10, and 15)  I tried all three.  It got so bad that I asked if he could turn off his 2.4Ghz spectrum on his wifi.  There were over 20 people in the room, all with devices probably attempting to assert their dominance trying to connect to networks.  It still didn't work.  It only worked reliably once I asked everyone to turn off their wifi for a few minutes so I could shoot the subjects.  This was only possible because I'm friends with the homeowner.  This would not be acceptable at any other venue.  In my own house, I don't have any issues.  I know this doesn't help, but other than overpowering the contested channels using more xmit power (which isn't allowed by the FCC) or changing to a different spectrum, most 2.4gHz devices are going to suffer.  It depends on the location you're at.  I get frustrated also, but short of a radio issue in the speedlites and transmitters, I don't know if there is anything Canon (or any other manufacturer) can do.



Past Gear:
1DX, 1DXII, 1DIV, 7D, EF 2.8 Trinity, EF-500mm f/4L IS USM, EF 50mm f/1,2L II USM
Current Gear:
R5C, RP, RF15-35mm f/2.8L IS USM, RF24-105mm f/2.8L IS USM Z, RF24-105mm f/4L IS USM, RF50mm f/1.2L USM, RF35mm f/1.4L VCM, RF100mm f/2.8L IS Macro USM, 4x 600EX-II-RT Speedlites, 2x EL-5 Speedlites, 1x EL-1 Speedlite

Anonymous
Not applicable

Could it be 5G cellphones causing the problem?

I mean, it's a different spectrum, but anything is possible.  Doubt it's the 5g.  There are a ton of 2.4gHz devices fighting for the limited space as it is.  2.4gHz is often better than the higher frequencies because it penetrates walls and windows better than the shorter wavelengths of the higher frequencies.  That's why there is a huge installed base of devices out there all trying to transmit and get priority.



Past Gear:
1DX, 1DXII, 1DIV, 7D, EF 2.8 Trinity, EF-500mm f/4L IS USM, EF 50mm f/1,2L II USM
Current Gear:
R5C, RP, RF15-35mm f/2.8L IS USM, RF24-105mm f/2.8L IS USM Z, RF24-105mm f/4L IS USM, RF50mm f/1.2L USM, RF35mm f/1.4L VCM, RF100mm f/2.8L IS Macro USM, 4x 600EX-II-RT Speedlites, 2x EL-5 Speedlites, 1x EL-1 Speedlite

gviper
Contributor

All l know is Godox works perfectly in the same area that the 600s constantly failed

That indeed seems to be the case.  I would of course, attribute that to the Chinese-made radios transmitting at a higher-than-allowed power.  I think the limit in the USA is 100 milliwatts or .10 watts.  External 2.4gHz radios can transmit at up to 1 full watt.  Europe is lower still.  Middle East and other countries have different limits.  China just doesn't care and is probably pumping out RF from their units at higher wattages than the Canon units.  (just speculating) However, it does seem to be an environmental factor that has reared its ugly head fairly recently.  Maybe the spectrum is over saturated and 2.4gHz is being clamped in certain locations.



Past Gear:
1DX, 1DXII, 1DIV, 7D, EF 2.8 Trinity, EF-500mm f/4L IS USM, EF 50mm f/1,2L II USM
Current Gear:
R5C, RP, RF15-35mm f/2.8L IS USM, RF24-105mm f/2.8L IS USM Z, RF24-105mm f/4L IS USM, RF50mm f/1.2L USM, RF35mm f/1.4L VCM, RF100mm f/2.8L IS Macro USM, 4x 600EX-II-RT Speedlites, 2x EL-5 Speedlites, 1x EL-1 Speedlite
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