Intermittent Studio Flash w/20D

[KHill]

On two different shoots, I have encountered intermittent flash failures using my 20D conntected to the Alien Bees remote transmitter/receiver system. I am using shutter priority mode set at 1/200 sec and ASA 200. Sometimes the flash triggers and I get a correct exposure. Other times nothing.

I've tested the sync cord and it appears to be good. I've also triggered the flash heads using the transmitter's "fire all" button without failures, i.e., the strobes fire correctly.

I spoke with the Canon rep and he indicates that the sync circuit closes everytime regardless of mode as long as the shutter speed is below 250 and no custom functions are engaged. I was shooting within these criteria.

So, before I send the transmitter and cord back to Alien Bees, am I doing something wrong?

Thanks ahead of time.

[Big Mike]

I don't know much about the AB transmitter...but that might be the weak link in your system. Maybe the distance is too great...or maybe it needs a clearer path from transmitter to receiver.

Also, why are you using Tv mode when with studio strobes? The camera's meter will be giving you an aperture based on the ambient light...and not the flash produced by the studio lights.

[KHill]

Good question, I should be in manual in this setting.

[FlashZebra]

On two different shoots, I have encountered intermittent flash failures using my 20D conntected to the Alien Bees remote transmitter/receiver system. I am using shutter priority mode set at 1/200 sec and ASA 200. Sometimes the flash triggers and I get a correct exposure. Other times nothing.

I've tested the sync cord and it appears to be good. I've also triggered the flash heads using the transmitter's "fire all" button without failures, i.e., the strobes fire correctly.

I spoke with the Canon rep and he indicates that the sync circuit closes everytime regardless of mode as long as the shutter speed is below 250 and no custom functions are engaged. I was shooting within these criteria.

So, before I send the transmitter and cord back to Alien Bees, am I doing something wrong?

Thanks ahead of time.
First, take a clean rag and buff both the center and both side connector terminals on the slave transmitter. Do the same thing on your cameras hotshoe.

I am a bit confused. Does the transmitter of this device connect to the cameras hotshoe?

If so, why is a sync cord in the picture ("I've tested the sync cord and it appears to be good").

Do you have it on the hotshoe, and have a sync cord attached from the transmitter to the PC port on your camera. If so, try taking off the sync cord and see it things are OK.

But, it should work via the sync cord attached also (or without it).

Alien Bee has fine customer service. Call them and they will set things right.

Enjoy! Lon

[hard12find]

I have had a PC cord problem with my bee's they will take care of you if you call, Jim