300D Black bar in images

[acrephoto]

I'm using a Digital Rebel with a brand new set of Alien Bees. I have my camera setup with a hotshoe pc slot and then have that plugged into one light. The results I've been getting are great except for one thing, across the bottom of my images I'm getting a black bar that fades into the image. Has anyone come across this issue before? if so how did you remedy it? I'm going to run some more tests this evening if I come up with anything new I'll post it here. Thanks!!

[slin100]

Your shutter speed is faster than the sync speed, 1/200.

[acrephoto]

that's all?!? If that solves my problem, I owe you a huge THANK YOU!!

[slin100]

It's the most likely cause. The camera's sync speed is the fastest shutter speed at which the entire frame is visible to the lens. At faster shutter speeds, the shutter begins to operate like a moving slit. Because flash operates at much, much faster speeds, the entire frame must be visible for the image to be correctly exposed.

The one exception is with FP (focal plane) flash, where the flash pulses multiple times as the shutter slit moves across the frame. This results in an evenly exposed image. The 420EX and 550EX support FP flash.

[drisley]

The 420EX and 550EX support FP flash.

That's really good to know!

[acrephoto]

it worked, you're AWESOME! It just goes to show what these forums really can do for you. Thanks a million.