420EX more consistent than 580EX?

[Toogy]

I just got my new 580EX a couple of weeks ago and really put it through the paces the last couple of days.
From what I have experienced, it seems that I need to play with the FEC WAY more than I ever had to with my 420EX.
Shooting in Manual mode with the shutter set to 1/80th and the aperture set at about F4 to F5.6, I had to keep adjusting FEC. With the 420EX, I never had to touch FEC and almost all my shots were good exposure.

Any idea why this is? I figured the 580 would blow the 420 out of the water and so far I am less than an impressed with it.

Do you figure I am doing something wrong? Or have a bad flash?

[scottbergerphoto]

Flash output is controlled by the camera body. On the same camera body with fully charged batteries, the consistency for the two flashes should be the same provided you are within the useable distance of each flash.
Scott

[AzzKicker]

you didnt say what camera you had

[Toogy]

20D

[PacAce]

Did you add + FEC or - FEC? And by how much. And what ISO were using?