Simple Canon Group Question

Really quite simple...why doesn’t Canon allow the master flash to be assigned to a group? It would make working with a on camera master flash and a remote slave easy to switch the contribution of light from each source. If I am reading the manual correctly the only way to do this right now is adjust the FEC on the camera/master flash and set a different value for the slave unit directly on the Slave. This isn’t that hard but it sure seems like it would be easier to make the master flash part of group A and the space group B and just adjust the ratio.

Sorry for the beginners question I’m just trying to understand everything these flashes can do. I just realized that the 430ex III-RT can be a radio master! I guess I was use to the old optical days and when the 600ex came out it was probably the only way to do radio master.

In group mode, the on camera flash is always "A". The slaves can be assigned other letters.

Best option buy the trigger so all of your flashes are fully usable.

Interesting point, I’ve been wondering why one would get the Canon radio trigger when the 430ex III-RT is cheaper. Since both serve as a master but obviously the flash can also be another flash it seems like the only downside is a small difference in bulk.

Canon Master flash units have always been assigned to Group A but, Canon left this fact out of several flash manuals over the years, either as an over sight or they thought every one knew (go figure!).

Canon must have fired the writers of the 430EX and 580EX series Manuals because in the 600EX-RT Manual, the fact that the Master flash is assigned to Group A, is mentioned twice in both the section on Radio Wireless then again in the section for Optical Wireless. So no matter the case, whether using Canons Optical Wireless system or the RT (Radio) Wireless system, and no matter the Wireless Mode, the Master flash is always assigned to Group A, and what ever settings you enter into the Master flash for Group A will be the settings for the Master flash.

It can be a bit of an inconvenience at times, when you are limited to only 3 Groups in the Optical Wireless system or when using the any of the non <Gr> modes in the Wireless RT system, when one of the 3 Groups is assigned to the Master flash. Using the <Gr> Group mode in the Canon Wireless RT system allows for 4 Groups of Slaves (Groups B thru E) and 1 Group (Group A) for the Master. So if you need more than 2 Groups for Slaves when you also need an "on camera" Master flash then using the Wireless RT system in <Gr> Group mode is a very nice option.

agv8or wrote in post #18531526
Canon Master flash units have always been assigned to Group A but, Canon left this fact out of several flash manuals over the years, either as an over sight or they thought every one knew (go figure!).

Canon must have fired the writers of the 430EX and 580EX series Manuals because in the 600EX-RT Manual, the fact that the Master flash is assigned to Group A, is mentioned twice in both the section on Radio Wireless then again in the section for Optical Wireless. So no matter the case, whether using Canons Optical Wireless system or the RT (Radio) Wireless system, and no matter the Wireless Mode, the Master flash is always assigned to Group A, and what ever settings you enter into the Master flash for Group A will be the settings for the Master flash.

It can be a bit of an inconvenience at times, when you are limited to only 3 Groups in the Optical Wireless system or when using the any of the non <Gr> modes in the Wireless RT system, when one of the 3 Groups is assigned to the Master flash. Using the <Gr> Group mode in the Canon Wireless RT system allows for 4 Groups of Slaves (Groups B thru E) and 1 Group (Group A) for the Master. So if you need more than 2 Groups for Slaves when you also need an "on camera" Master flash then using the Wireless RT system in <Gr> Group mode is a very nice option.

Thanks for the reply! That's very helpful! Very good point about the manuals as I specifically looked for group information for the master in the 430ex III-RT manual and could not find any mention of it! At least they got it right in the 600EX manual.

I thought it was also weird that Canon just says in their manual "if you assign a flash to group d or E it won't fire". That's very confusing until you learn about the GR mode.

Is there any benefit I am missing to get the ST-E3-RT over the 430EX III-RT? They are about the same cost (in fact I think the 430 is cheaper.

I used a 430 III RT set to "Master" to fire another set to "Slave" for a few months before getting an ST-E3-RT. The only practical difference I've found is weight.

Have a look at this excellent YouTube video by Syl Arena on Canon's Group Mode: https://www.youtube.co​m/watch?v=FQfCFh-av2o

Sdiver2489 wrote in post #18531557
Thanks for the reply! That's very helpful! Very good point about the manuals as I specifically looked for group information for the master in the 430ex III-RT manual and could not find any mention of it! At least they got it right in the 600EX manual.

I thought it was also weird that Canon just says in their manual "if you assign a flash to group d or E it won't fire". That's very confusing until you learn about the GR mode.

Is there any benefit I am missing to get the ST-E3-RT over the 430EX III-RT? They are about the same cost (in fact I think the 430 is cheaper.

If you're wanting to kill two birds with one stone and be as minimalist as possible then a 430EX III-RT in lieu of an ST-E3-RT makes the most sense. I did not have any other options, other than 600EX's and ST-E3-RTs, at the time I moved up. If the 430EX III-RT had been an option I would have bought several of them in lieu of some of my 600EX-RTs (which I paid $600 each) and in place of at least one of my ST-E3-RTs.

As a Canon fan boy I am very fond of the RT system and love the 600EX-RTs but, if I was starting from scratch, with todays options, I would seriously look at going all Godox. I say that even though out of lazy sentimental reasons I have yet to sell any of my Canon 600EX's and ST-E3-RTs in spite of having moved to currently using mostly Godox equipment. Also the 600EX-RT is hands down the best "on camera" flash I have ever used and even though Godox Speedlites are very good quality for "off camera" use, the design of the way the head swivels and tilts is IMO one of the worst designs I have used. But, if you didn't know any better or were not as anal about such things as I am then one (most) would never give that a thought.