Master slave out of sync or am I stoopid.

550EX and 580EX behaving oddly. When set as master/slave in ETTL the slave

gun seems to fire significantly late. No matter which is used as master or

slave. In manual mode they fire together. It's not a matter of pre-flash and

flash - both have finished on the master before the slave pops. This is

testing off camera just now trying a guess set-up before going out on a job.

Last time I used the set-up the 550EX refused to fire at all outdoors - I put

that down to conditions and it wasn't critical. Am I missing a setting (and

god knows they are complex settings) or have I a repair bill in the

viewfinder ? All help appreciated.

Are both in same slave group?

no 580 is A and 550 is B

Derek try it with the switched on camera. If you test the setup with the flash-button of the master flash and the camera is switched off(the exposure meter no longer active) you get a delay in firing the slaves so you can control whether the system is working. I guess it is the same if you test the setup without a camera at all.

 

Gerhard

I'll try that thank you.

If they're in different slave groups there is a delay (when firing a test), so you can see visually which flashes are in which groups.

 

Test them in the same group and I'll bet they fire together.

ETTL means the camera participates through the lens in the flash exposure computation. If the camera is Off ? - all bets are off.

No firing in the same group makes no difference - still a delay. But firing on camera and all is well - in sync and working as advertised. Now could I ask you guys where you learned this because I have trawled through my written documentation and everything I had time to read on the net (inc canon's own info) and didn't find reference to this diagnostic off-camera firing anywhere - is there a good source I have missed ? Thanks to everyone - Photo net does it again.

Derek,

 

 

Hard to say where I red it (I just use flash too often to remember) but it may be in the user-manual of the ste-2 or 550EX.

 

http://www.hofmann-photography.de/html/mouthmarks_39.html

 

regards Gerhard

I just discovered it for myself when playing with my setup.

Well thanks for passing it on. Dear canon is there anything else we should know and we're not being told ? There was another instance in my ken involving image stabilising switching automatically to/from pan mode in certain circumstances - Canon secret teased out by a brainy guy, anyway thanks to all - I'll be better prepared next time