Flash synch issues

[mvonditter]

I have a 550EX that I use as the master and a 420EX that I use as the slave. The problem is that the 420 fires a good half second after the 550, that’s about 30 times to slow and which of course totally defeats the purpose. Clues or suggestions? Am I doing something wrong?

[tpinchback]

What mode are you using?

Sink=Sync

[mvonditter]

Primarily P, however it doesn’t seem to care. And if this can’t be solved the 420 will end up in the SINK. :-)

[Jim Larson]

That does not sound right. . .I do not have that problem.

Master set right?

Slave set right?

Are the master and slave on the same channel? (must be yes) Same group (you probably want one in A and one in B)

[DaveG]

I have a 550EX that I use as the master and a 420EX that I use as the slave. The problem is that the 420 fires a good half second after the 550, that’s about 30 times to slow and which of course totally defeats the purpose. Clues or suggestions? Am I doing something wrong?

Are you noticing this hesitation when you shoot or when you use the test button on the 550? If you use the 550's test button there is supposed to be some hesitation before the 420 fires. I expect that's so you can clearly see that the 420 is firing.

You can also get this delayed pop from the 420 in another way. If you haven't fired the 420 for about five minutes or so, then the 420 will go to sleep. When you then try to take a real shot with the camera and the 550, the 550's pulse will just wake it up the 420 and you get that delayed flash pop out of the 420. That shot will be ruined but the next shot should be fine.

I'm just brainstorming here, so let me know if this is the solution.

[mvonditter]

420 is set to slave group A ch. 1. 550 is set to master ch. 1. Ok, 1'2 second late might be a bit much, however it's at least 1/4 of a second. I would expect them to fire at the same time.

[DaveG]

420 is set to slave group A ch. 1. 550 is set to master ch. 1. Ok, 1'2 second late might be a bit much, however it's at least 1/4 of a second. I would expect them to fire at the same time.

Although this doesn't have much to do with your flash delay (I think) your 420 should be set to Group A and the 550 set on Group B. If you don't do this you won't be able to use any of the ratioed lighting since both flashes will try to output the same.

I have to say that I was told to set the 420 to B and then the 550 will default to A. It works fine this way except that the ratios are reversed. A 3:1 lighting ratio has to be set up as a 1:3 for example. I've been doing this for well over a year now so I'm not going to switch to the "correct" way now, but I thought that I'd point it out.

The channel is the "frequency" that you are communicating on and all the flashes should be on the same channel.

[mvonditter]

DaveG....you solved the problem. Thanks.......and my shrink hates you. No money from me this time. :-)

[DaveG]

DaveG....you solved the problem. Thanks.......and my shrink hates you. No money from me this time. :-)

OK, how did I do that? Were you using the test button, had the 420 gone to sleep, or was it the Group selection?

[scottbergerphoto]

The master on the camera defaults to Group A. If you don't want to use ratios you can set the slave to any group, even A. If you want to use ratios between the two flashes you set the slave to Group B. If you are using two 550EX's you can also set both flashes to Group A and dial in FEC independently on each flash (no ratios). They both have to be in the same group to do this. This has nothing to do with channels. Channels are used to avoid conflict with another photographer. All your flashes must be on the same channel.
The reason you use ratios of 1:3 and not 3:1, is beacause the on camera flash(Master A) is the fill light and the off camera flash (slave B) is the main. I reccomend upgrading your 420EX to a 550EX because of that. I use 3 550EX's and ratios (A:B):C
http://www.pbase.com/scottbergerphoto/ayana_bailey
Scott