I have been looking at the instructions for the speedlite 580ex here for any idea how to fire the flash from the built in camera flash, but it has not helped.

Does anybody know if it is possible to fire it with a cameras in built flash?

I'm not sure if this has been read incorrectly. If I am not mistaken the flashgun can recognise when a flash goes off (a peak in light) and fire its own flash also?

I was watching a video on youtube where a buzz lightyear camera fired a remote flash gun, by its own flash firing.

  • 1
    With which camera?
    – mattdm
    Feb 17, 2013 at 1:01

4 Answers 4


The flash that David Hobby's using in that "cheap camera challenge" video is a Yongnuo YN-460--it has a built in "dumb" optical slave, which is a simple "see a flash burst--fire flash" sensor-based way of triggering a remote flash.

The 580EX does not have this capability. You can add the capability with a Sonia green-based optical slave, but then your main problem is that the 580EX also has no sync port to attach a slave to, so you'd have to get a hotshoe to sync port adapter or modify/replace the flash foot to include a sync port to plug the slave in. At which point you might as well just spend the same amount of money on cheap radio triggers (e.g., Yongnuo RF-603IIs).

What the 580EX has is a "smart" optical slave--one that speaks Canon's wireless flash signalling protocol, which is done with preflashes in the near-infrared range. To use the 580EX as a Canon wireless slave, you need a Canon wireless master unit. These are built into the pop-up flashes of the T3i (600D), 60D, 7D, and later cameras, but not in any of the earlier models. So, with, say, a T2i, you'd have to have a master unit on the camera hotshoe, and that would be an 90EX, ST-E3, 550EX, 580EX, 580EXII, or 600EX-RT. There are some third-party flashes from Metz, Nissin, and Yongnuo that can also be masters, but these are typically going to be the high-end expensive models.


You'll need to check your camera instructions.

Only the newer Canon DSLRs (eg 7D, 60D) have the built in flash able to work as a Speedlite transmitter.

If you've not got one of the more recent cameras, you'll have to consider other options for triggering a remote flash (eg ST-E2, another 580, or - if you can accept manual only flash - an optical slave or one of the several wireless transmitter / receiver combinations that are available).


That function is provided by the camera body, not the flash.

If I am not mistaken, currently only the 7D, 60D and 650D offer that feature.

We can expect to see this feature on most upcoming Canon DSLRs with a built-in flash, too. (5D and 6D does not has a built-in flash)


The flash in question doesn't have an optical slave, as far as I can tell, it only supports Canon's proprietary wireless flash system. If you want the flash to fire when it detects light, you'll need a small optical trigger. These are about $10 here in Toronto, Canada. Attach it to the flash hot shoe, turn on the flash, and fire another flash at it.

If you want greater flexibility without Canon's speedlite transmitter, you'll need wireless triggers like the Cactus v5, pocket wizard, etc.

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