Canon 550EX [used] vs Yongnuo YN600EX-RT II [new]

Kit.

EOS Rebel SL2
Apr 25, 2011
512
139
#21
550EX will work on even newest camera, just wont measure light according to latest standard.
Flashes don't measure light (or at lest not in E-TTL. They did it in A-TTL). They just pre-fire in their group. Then the camera measures the light and tells the group how strong it should fire.

Groups D and E are radio-only and likely aren't supported by 600D even with an RT master.
 
Sep 9, 2012
1,125
13
hhaphoto.com
#22
Groups D and E are radio-only and likely aren't supported by 600D even with an RT master.
I agree; a quick tinker with my 40D indicates that a YN600EX-RT II will trigger other RT lights given a couple of caveats:

ETTL and manual modes work but only for lights in groups A, B and C;
Multi I'm not sure works properly; and
Group works but only for manual mode for each group and only for A, B, C although it does allow different power settings.

The YN-E3-RT on legacy mode may be a partial workaround but that's another story. In any case I maintain that few extra bucks for RT triggering is worth it even if your current camera only partially supports it.

Jim