Using 580EXII on 5D

[Maleko]

Thanks for the response guys, tried all that and no difference even at high ISO.

I also noticed that with shutter priority mode on and flash in manual it sets the aperture to 22, no matter what shutter speed I select...

very strange how on the 50D it doesn't do this.

[gkphoto]

do not have a 5d however, on the 7d there are the flash controls in the camera menu and i wonder if something is setup in that menu system? if it exists. total shot in the dark as i don't even know if that exists on the 5d but i have left settings in there on my 7d and then come back a week later and didn't remember i had done them.

[clemmb]

Just tried my 5D and my 1DnkIIn with flash in manual and camera in P mode. I get the same thing you do. 200 @ f22 or 250 @ f22 with the 1D. These two camera bodies both came out at the same time.
I am not sure why you would want to operate in P with the flash in manual? I cannot imagine you getting a good exposure. If the flash is in manual the camera needs to be in manual.

[Maleko]

At least this isn't just me then!

I just got stuck in a way of using P mode on the 50D and then using the flash in manual, I used to use that for quick snaps where I would increase the flash power to increase exposure.

I will just start using Aperture mode more for that, which I should do anyway really!

Really strange how it is different on the two cameras though...