The following are two articles I wrote for the old site after getting 600EX-RT speedlites and 5DIII cameras last year.
First article from other site
Here is a quick test to help me get a feel for how efficient a 600EX-RT would be on a stand with STE3-RT in the hot shoe for shooting around a location quickly. (Think bride getting ready at home. 🙂 )
Unfortunately, I didn’t have a bride handy; fortunately our year old Siamese cat Mac is always wanting to be the center of attention. He also happens to love playing on the counter in the master bath.
The 600EX-RT was on a light stand with my white foamie thing attached. Flash head toward celling, foamie thing reflecting light toward wall. Away from room. Flash was in front of window to simulate light coming from there.
Ambient exposure was two stops below camera settings. 1/10 shutter, ISO 1600, F 4.0. The shot of Mac is at 1/50 shutter, ISO 1600, F 4.0. Flash is about 6 feet away from the counter camera left.
This testing has demonstrated, to me at least, that the 600EX-RT along with the STE3-RT are up to delivering the goods.
I especially like the recycle indicator on the display and the ease with which power can be changed when using multiple groups.
So far, I’ve just scratched the surface of the system’s capabilities.
So more to follow 🙂
I wanted to do some additional testing with my 600EX-RTs to find out just how well they will work for fill flash with the subject in shadow and the background sunlit. More or less a normal wedding day situation. 🙂
I also wanted to see what the impact of F stop would have on the background; a line of trees about 40 ft behind the subject. And I got the additional benefit of seeing how good the off center zone focus capabilities of the 5D3 will be capturing focus since I was the only subject available. (So bear with the self portrait examples. 🙂 )
5D3 with 85mm F1.2L II on a tripod about 8 ft from subject. I set the AF to lowest right using the zone capability. That showed there were 4 AF segments active.
The camera was set to Av, ISO 50, -1 EV exposure compensation, metering is evaluative.
Flash was on a stand about 4 ft from subject camera left and looking down about 45* through a Westcott 32″ collapsible umbrella. Flash was ETTL with HSS activated and no flash exposure compensation.
The focus at F1.4 isn’t precise because of the hit or miss nature of a self portrait.
This is the result at F1.4, 1/3200;
This is at F4.0, 1/800;
and this is F8.0, 1/100; Here the forehead reading was about 1/2 stop hot. Pulling exposure down -.5 brought the forehead reading to within 2 %. All the shots with shutter speeds above sync speed had readings within about 2% of each other.
This was accomplished with the 600EX-RT, realistically the same results would occur with a 580EX or 580EXII, or a Nissin Di866 etc.