Flash ration between master (550EX) and slave (430EX)

[lotsawa]

If I use the 550EX as master on the camera and the 430EX as slave

(wireless ETTL, not manual mode), is it possible to control flash

ration between these two flashes?

 

The 550EX's manual only explains flash ration between two or three

slave flashes (or flash groups, to be more exact).

 

One solution would probably be to set the master as group A and the

slave as group B and then follow the normal procedure of setting a

flash ratio between these groups. Don't know if that's possible.

 

Another solution might be to use FEC on the flashes. But can FEC be

set seperately for each flash or does it control the flash output as a

whole?

 

(I found a 4 years old thread that also covers this subject more or

less, but is quite confusing for me ...)

 

Thanks for your insights,

Christof

[bens]

yes, just did it tonight, put master in a and slave in b, turn ratio on. i think its covered some in the manual after discussion about the two slaves. i think you mean the 420 not 430.

[les]

http://photonotes.org/articles/eos-flash/

[bill_goldman]

The correct procedure is as you describe it in your first assumption:

 

"Set the master as group A and the slave as group B and then follow the normal procedure of setting a flash ratio between these groups."

 

It's also possible to set FEC on all units by setting it on the master; or you can set it on each individual Speedlite.

[lotsawa]

Sorry I forgot to consult the eos-flash bible, wherein it is written:

 

"Note that if you?re using a 550EX or 580EX as a wireless master unit (either on-camera or connected to it using the off-shoe camera cord) then it defaults to group A. If you want to control the ratio of slave unit output to master unit output be sure to put the slave units into group B."

 

Thanks a lot.

[lotsawa]

Ben, I meant the 430, not the 420.

[jim_larson1]

430, 420, and 550EX will all act the same when in "slave" mode. The only differences are the ability to individually place the flash in manual and the individually put FEC on the flash. Personally. . .I find that the ratio control is more than adequate for most situations (although. . I have not played much with key lights)