600EX-RT Part I

Did a quick test to see how the 600EX-RT works along with a YN560 manual flash.

YN 560 in Phottix octa about 3 feet from mannie. 600EX-RT on camera set to ETTL with -3 FEC to minimize its influence on the shot.

YN560 was set to S2 and at 1/16 power. ISO 200, 1/200 at F5.6

The image is about 1/3 stop below prefect exposure based on some minor playing with white, black highlight and shadow sliders in LR 4 with a medium tone curve applied. That gets the white and black squares on the color checker just about where they belong exposure wise.

One wouldn’t be able to use the YN560s this way at a wedding or event where people are popping P&S cameras, but it does mean I have access to my low cost manual speedlites to augment the ETTL kit.

Forum questions;

I got some questions from forum participants when I posted this in the Photography-on-the-net lighting forum;

If you use manual power settings on the Canon RT gear can you still use the S1 slave mode on the YN-560. Syl Arena appears to have done this with optic slaves but I’d like to confirm.

Also the main reason for that question is if there is actually any pre-flash in manual, so a light meter could be used or not? Does the test fire button fire at the correct power level?

Third question is can you hook up another manual radio trigger to the PC port of the camera and fire other manual flashes/monolights in sync with the Canon RT system.

and the answers are;

YN560 fires as expected in S1 mode with 600EX-RT set to manual on camera. 1/200 shutter, ISO 200, F5.6 YN560 at 1/16 power. 600EX-RT at 1/128 power to minimize contribution to exposure.

YN560 fires as expected with RF-602 receiver mounted and transmitter attached to PC connection on 5DII. However, the shutter has to be slowed to 1/100 to get rid of shutter curtain shadow. 600EX-RT and camera settings were the same as before.

To confirm that it was the PC port on the camera, I placed the RF-602 trigger in the hot shoe. In this configuration 1/200 shutter speed did not produce a shadow. So, there is something about the PC connection that requires slower shutter.

and some follow on;

Thanks for testing that.

Where you firing a second 600ex-RT off camera though? This is where I’m wondering about pre flash, it won’t have any with just an on camera flash in manual.

With the PC port, same question I guess, is the Canon RF wireless causing the slow down or its no different just moving the RF-602, with no Canon RF wireless involved.

The RF-602 are pretty slow triggers though, I’m not sure why the PC port would do it, but it doesn’t take much for the sync speed to start dropping with those.

Again, good questions, and the answers are;

With second 600EX-RT off camera the YN 580 fired when expected using S1.

I did this with the 600EX-RTs in ETTL as well as M mode. No difference.

As for the reduced shutter speed with RF-602 is plugged into PC outlet on camera. The shutter speed needs to be reduced to 1/100 even without a flash in the hot shoe.

I have always been able to use my RF-602s at sync speed when the trigger is in the hot shoe. It may be that there is an earlier fire signal there for some reason.

And some more questions;

How well does the new RT flash system work with the 5D Mark 2?

What features wont work properly unless used with a 5D3?

And the answers;

All of the testing I’ve been doing has been with a 5DII.

And, I’ve been focusing on the HSS and similar considerations.

More questions;

Is it true that this system cannot fire flashes with rear curtain sync in wireless mode? This is a dealbreaker for me. Why has Canon engineered this flaw into their flash system? Same problem with the old flashes using Radiopoppers/PW


This appears to be universal with wireless connections. The best I can determine from reading and talking to tech support with Pocket Wizard ControlTL is that the propagation delay with radios makes the rear curtain sync timing impossible to do with sufficient accuracy.

That said, it would be nice to have it incorporated. For me, HSS is more valuable.

Now we’ve added an STE3-RT to the mix;

STE3-RT arrived so I gave it a quick test with three 600EX-RTs.

One in group A, one in group B and third in group C.

The A:B ratio was set to 2:1. Each 600EX-RT was in a Phottix octabox about 3 feet from Mannie.

The third 600EX-RT was mounted on a stand and zoomed to 200mm as a hair light. Using the STE3-RT I set the ratio between A and B and then set the power for C. It was set to -2 FEC. Obviously still quite hot. It was about 3 feet above Mannie.

This test image was shot at 1/1600 shutter, F5.6 and ISO 200.

The Lightroom processing is Exp +1.0, Whites +0 and Blacks +0 with a strong tone curve.

The blacks in Mannie’s hat are about 6% and the “specular” highlights in the edges of the hat are 89% There is no noise visible in the blacks as one would expect at ISO 200.

The 600s in A and B groups were working hard based on the recycle indicator on the STE3-RT. The one in group C recycled almost instantly, indicating a much lower power requirement.

ย One more performance evaluation:

I know everyone is getting tired of seeing Mannie, and I wanted to test the consistency of the 600EX-RTs when changing F stop. So it seemed appropriate to setup a quickie table top product shooting scenario.

One Octa with 600EX-RT above camera and just right. (B). Another Octa with 600EX-RT about 45 degrees from subject camera left. (A). Both Octas have the diffusion panel installed. The third 600EX-RT was in its little foot stand under the shooting table aimed at a white foam core board behind table and tilted down toward light just a bit.

A:B ratio was 4:1 and the C speedlite was set to -2.

The image was brought up 2 stops exposure in Lightroom shadows was set to +25 and clarity was set to +50.

The first image is 1/100, F11, ISO 200 the second image is 1/200, F22, ISO 200.

There is just the subtlest difference in contrast between the two. Not sure why in the JPG, its much less noticeable in LR. Anyway, both are well within acceptable range for this kind of product shooting.

600EX-RT off camera test.

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. ๐Ÿ™‚ )

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 ๐Ÿ™‚