Before the rush

Before the rush
by evan-pak

Submit your Photo
Hall of Fame

Please participate in Meta
and help us grow.

Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

How can I trigger a 550EX while using two 600EX-RT's? Is there a way to set it so that the 550EX will just see the flash pop and trigger itself?

share|improve this question

This article from Canon seems to indicate that the 550EX uses the same optical wireless sync as the 600EX-RT when operating in optical mode rather than radio mode. You should be able to set the 550EX and one of your 600EX-RTs as optical slaves and control them using the other 600EX-RT as an optical master. (Alternately, you could theoretically use the 550EX as a master, but it might lack some of the feature support for the 600s.

share|improve this answer

Canon EX series flashes don't have an option to be triggered as a slave based on generic light from another flash (that isn't encoded as a 'master' signal).

If your body has a PC terminal, you can use a wireless trigger attached to the PC terminal to fire the 550EX using manual power control from the flash's own control panel.

share|improve this answer

The 550EX only speaks the optical wireless protocol, not the RT radio one, so if you used the optical wireless eTTL Canon system, you could play with all three lights.

If you want radio, however, since Canon doesn't make RT add-on units, you'd have to get a set of radio triggers for all three flashes.

You could also get a Sonia green-base optical trigger, and as along as the 600EX-RTs were in radio mode and not pre-flashing, that would work to set it off. The only problem is that the 550EX, iirc, does not have a sync port to attach the slave to, so you'd either have to mod the 550EX, or add a hotshoe to sync port adapter.

share|improve this answer

Why Not just set the 600EX-RT as Master using OPTICAL and setting your 550EX of camera (or anywhere in optical range) as SLAVE. The 600EX-RT should trigger the 550ex.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.