I own a Rebel T6i and a apeedlite, a Yongnuo YN-565EX III. I've tried several times to trigger the flash off-camera (on a tripod with a softbox) and I've had some very unsatisfactory results.

With the speedlite on a tripod I've set it to ETTL slave mode (Sc mode). On the camera on the camera I went to Flash Control >Built-in flash settings in there I've set the following settings:

  • Flash firing: Enable
  • E-TTL II meter: Evaluative
  • FLash sync. speed in Av mode -> 1/200
  • Channel: 1
  • Group: A

Here's a image of the flash settings as it is right now: Flash Settings

On Built-in flash settings I have the following:

  • Flash mode: E-TTL II
  • Wireless func: (Set to the icon of the dedicated flash only)
  • Channel: 1
  • Firing Group: All
  • Exp. Comp: 0

Here are some images of my camera settings:

First screen: First screen

Second screen: Second screen

I have the sensor turned to me as I take shots of my speelite on a tripod. I'm literally taking pictures of the optical sensor:

Here's how the speedlite is positioned: Speedlite position

I think it's important to say that I'm shooting on full manual mode. Now to the problems.

  1. Most of the times when I use the pop-up flash to trigger the speedlite, the built-in flash goes off, but the speedlite isn't triggered, even though I'm pointing the built-in flash directly at the sensor at a distance of around 1.5 meters (about 5 feet I guess). The speedlite goes off on an estimate of one time every ten attempts. The batteries are new and I wait about 5 seconds between each new attempt.

  2. When the speelite goes off, most of the time it doesn't affect the exposure of the image. It's like, it's out of sync with the camera or something like that. My room it's pretty dark, and even when the speedlite goes off the image is completely dark.

  3. Sometimes (a good amount of times) the pop-up flash of my camera doesn't go off even though it's set to go off and my room is completely dark. Does the built-in flash have a recharge time or something like that?

I've also tried using the speedlite (and built in flash) on manual slave, instead of E-TTL slave, but had the same problems.

I'm trying to learn off-camera flash techniques and I was relying on the optical trigger, as I don`t have a wireless one, so if anyone has a suggestion on how to fix this I'm eager to try.


1 Answer 1


I think one possible issue is that you have the camera's "wireless master" settings set to expect you have a Canon EX speedlight mounted on the camera's hotshoe as your optical master: Wireless func. is set to a speedlight icon, not the pop-up flash icon. Change that to the pop-up flash, if you're using the pop-up flash as your master. And, obviously, you'll have to pop it up. :)

The second possible issue is that both the pop-up flash and your external speedlight both have recycle times, so yes, you do have to wait between shots. If you're using NiMH rechargeable batteries, a full-power recycle can take around 3 seconds, but if you're using alkaline batteries, it can take as much as 7 seconds, so a 5-second wait may not be quite long enough. The YN-565EX III has a recycle beep function (Fn14) you may want to turn on, so the flash gives an audible signal when it's ready to fire again to avoid trying to trip it too early.


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