The R6 alone cannot fire the flash off-camera... however, there are accessories that can make it possible.
First, I assume your flash is NOT radio controlled and triggered. AFAIK, there was no 430EX II that was radio triggered, but I may be wrong. (430EX III-RT is radio triggered.)
I'm also going to assume that you have tried the flash directly IN the camera's hot shoe and it works properly. (I don't have an R6, but looking at images of one it appears to have the standard five contacts used with older flash like yours and mine).
If my assumptions are correct, it means that there are two ways to control and trigger your 430EX II off-camera:
1. Wired. An off-camera shoe cord fits into the camera's hot shoe and has a hot shoe at the other end where the flash mounts. Canon sells off-camera shoe cords, but they are limited to about 3 feet. I just checked at B&H Photo and see they offer a two or three 3rd party cords that are around 6 feet long, a Movo cord that's 16 feet long and a Vello cord that's 33 feet long. Off-camera shoe cords at B&H Photo.
2. Wirelessly. The 430EX II and many other Canon flash (that are NOT "RT" or "radio triggered) use optical communication and triggering for remote, off-camera operation. The sensors on the flash are under the transparent red panel on the front. This optical control and triggering system uses near-IR light to communicate. When set up the red lens must face the camera (rotate the flash head toward your subject), must be line-of-sight and cannot be too distant... maybe 40-45 feet at most. But workable distance varies a bit depending upon ambient light conditions... when that's low, the flash might be okay farther away. But if ambient light is strong it can limit the distance.
In addition, you need a "controller unit" in the camera's hot shoe. This can be a flash that can act as a "master" (550EX, 580EX, 580EX II or 90EX) or it can be Canon's compact ST-E2 Speedlite Controller (discontinued, buy used... the newer ST-E3-RT and ST-10 cannot be used as they are radio-only.) When a flash is being used as the controller, it can be set to lower power or turned off entirely, so it only serves to control the off-camera flash. The 500-series flashes are large... the 90EX is tiny and low-powered.
Used Canon ST-E2 at MPB.com.
Used Canon 90EX flash at B&H Photo.
Used Canon 580EX & 580EX II flash at B&H Photo.
The above methods provide both control AND triggering of the flash off-camera. You can use the flash in ETTL mode, where the camera's metering system is used to automatically control the flash's power output.
A third possibility would be to set the flash to manual mode and use some other form of triggering... Wired with a simple PC sync cord or wirelessly with a simple radio transmitter/receiver setup such as the inexpensive Vello Freewave Fusion set.
The above transmitter/receiver set and other, similar sets only provide triggering. There are more complex radio sets designed to control multiple groups, some of which are able to translate into optical control for flashes like the 430EX II. I haven't used these and can't say if they provide full function and are reliable.
Radio control and triggering can be done over much longer distances... 100 feet at least, often more and sometimes much more. Radio triggering also doesn't rely upon line-of-site. While some objects and materials might interfere with communication and reduce the effective distance, it is easier to "hide" flashes with radio control and triggering. In most cases the radio systems also can handle a larger number of off-camera flashes and provide more channels or groupings.
Again, I don't have an R6, but it appears the hot shoe is "standard", though it may have some added connectivity (for a video microphone accessory?)
P.S. The ST-E2 and the flash with optical control also can provide a Focus Assist using near IR light, to help the camera and lens focus in low light conditions. I don't know if this is any different with the R-series mirrorless, but it can be helpful at times working with the Canon DSLRs. Also, some of the cameras with a built-in flash are able to communicate with these optical flashes too, using their own built-in flash as the controller.
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Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2), EOS M5, some other cameras, various lenses & accessories
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