EOS 50D - AV Mode - Flash - Long shutter speed

[sputnik]

I have a EOS 50D.  I am getting ready to shot a party so I am testing out what settings I should use.  I tested in a low light room which according to my light meter is aperture 2.0, Shutter 1/30, at ISO 1600.  Dim but you can still read in the light.

My plan is to use AV mode and set the aperture to 5.6 or 8 so I can make sure I have some DOF so people will mostly be in focus.

I set my camera to ISO 1600, AV Mode, Aperture 5.6, ISO 3200  and attached my Canon speedlite 430 EX to the camera in ETTL mode.

The camera took the picture at:  5.6, ISO 3200, 1/6.  The flash fired.

I tried P mode.  The camera took the picture at:  1/60, 3.5, ISO 400.  The flash fired.

I tried M mode.  The camera took the picture at: 1/250, 5.6, ISO 400.  The flash fired.

All photos had good exposure which showed the camera and flash were talking and worked out the correct level of flash.

The problem I have is I want to take my party pics but I want a shutter speed that is going to freeze the action versus a shutter speed of 1/6 which won't.  Seeing how the light is not that dim if a person is moving or I am not using a tripod the picture is going to be blurry. It was in my tests.

Is there a way to get the AV mode when the flash is attached to use a sync speed closer to 1/125?

[TCampbell]

I don't have a 50D (I do have a 60Da which was just the next generation).  I think you should have a setting for shutter speed when using flash in Av mode.  The default is "Auto", but there should be an option labeled likely "1/60-1/200" and another that's just "1/200" (It might be 1/250th).  The fast speed is basically whatever the max flash sync speed is for your camera.

When you use a flash in Av mode, the flash is treated as 'fill flash" - meaning the camera normally will meter and expose as if there is no flash (so if it required a long exposure with no flash, it will require a similar long exposure with flash).

The menu option that lets you pick the "1/60 - 1/200" range (when using flash in Av mode) basically prevents the camera from using any speed that would be too slow for hand-held photography.  

I change that to be the default on all my camera bodies.  I don't ever use the "auto" setting because it can select a speed which is much too slow for a hand-held shot.

[Ray-uk · Accepted solution]

TCampbell above is quite correct but the easiest solution is to shoot in manual mode.

Using ETTL flash set the shutter speed to about 1/125 and any choose your own aperture as you are now doing in AV mode.