Will I get full functionality from a Canon 600EX-RT flash with a ST-E3-RT trigger on an Rebel XS?

Question

I have a Canon Rebel XS (1000D) and I use the 430exII flashes with the Cactus V5 transceivers. They all worked well, but of course with no TTL — everything, everytime, in manual. I have achieved great shots, but in situations where I need to be fast, there is no time so set up all of this. So, I am looking to buy the 600EX-RT for strobist use (off camera flash).

I know that my Rebel XS does not have a way to trigger the flash remotely, so: if i use the Canon ST-E3-RT trigger mounted in my camera's hot shoe, can I get all of the 600EX-RT's funtions?

And, is it is the same if I use the Yongnuo YN-E3-RT?

Answer 1

You'll certainly be able to use ETTL with the 600EX-RT and ST-E3-RT. However, you won't be able to use the ST-E3-RT to control your 430EX II units, as it lacks optical triggering. You could use the 600EX-RT to control those 430EX II's optically, including using ETTL, but that kinda defeats the purpose of buying the radio-capable units.

Some options:

• Skip radio for now and stick with your 430EX II's. Pick up a used or refurbished flash that you can use as an optical master -- the 580EX, 580EX II, or ST-E2 would all work. Canon's tiny 90EX can be used with some bodies as a master; I don't know if the Rebel XS is among these, but if it is then this is a very inexpensive way to go.

• Go with Canon's radio system and start to phase out your older flashes, or keep an eye out for ways to make them radio-capable. I read recently that Yongnuo will introduce a receiver that will work with Canon's radio system, so you could use your 430EX II's with the 600EX-RT (without switching to optical triggering). (Sorry, can't find the link right now.) The down side is that each receiver will be priced around $90.

• Upgrade your triggers. The reason you're not able to use ETTL with your current speedlites is that the Cactus V5 triggers don't do ETTL. But there are existing radio triggers that work with ETTL, and switching to these will solve that problem for you. However, those triggers aren't compatible with Canon's radio triggering system.

Answer 2

No, you will not get the full functionality of the 600EX-RT/ST-E3-RT system with your XS. But you will get all the functionality you would have with the 430EXII or a 580EXII over optical--most notably, remote power control, eTTL, and high-speed sync.

The Canon RT radio system added some functionality to the older optical triggering system that you can only have access to if you use a 2012 or later Canon body with the RT gear. The Canon XS/1000D is from 2008, so it predates the ability to do the following functions with the RT system:

• 4-digit ID code, which with channel settings, allows for thousands of discrete channels
• Remote shutter control over the camera from the flash.
• Groups D and E.
• Gr mode (i.e., groups can now independently be set to MULTI, eTTL-II, or M modes as well as turned on and off)

If you eventually get a 2012 or later Canon body, these functions and the quick-access flash control panel will be available to you.

And, obviously, the 430EXII can't work in concert with a 600EX-RT with a E3-RT transmitter as the master unit since it doesn't speak radio on its own.

There is a much lower-cost alternative to getting eTTL and HSS with your XS and 430EXII than going all-out on Canon RT gear, and if you're willing to take the risks inherent in budget Yongnuo gear. You could just swap your Cactus V5 triggers for Yongnuo's YN-622C (or Phottix Odins, or Pixel Kings, or other TTL-capable radio triggers). The YN-622C triggers will communicate most of the hotshoe protocol and will allow you to do eTTL and HSS over radio, as well as give you rudimentary groups mode and wireless 2nd-curtain (which even Canon's own RT system won't). Also, unlike the Canon RT gear, it's compatible with non-Canon gear for manual triggering with remote power control.

Or, if you really want to move to the RT system, but can't throw all-in just yet, you could also go with the YN-E3-RX receiver for the 430EXII and either an ST-E3-RT or the YN-E3-RT, and use the 430EXII in the RT system, with ID codes, Groups D and E, and Groups mode capability.

The YN-E3-RT has been used by quite a few people as a replacement or substitute for the Canon ST-E3-RT and it should be compatible with a 600EX-RT. Be aware, however, that the YN-600EX-RT is not an identical clone of the 600EX-RT, and is missing a few features the Canon has, such as optical mastering capability and an external sensor. OTOH, it also has dumb optical slave modes and can be used in a Nikon CLS setup. :)