40d shutter too slow with flash

I've apparently changed a setting. In Av mode, with popup flash, indoors the flash fires and the shutter remains open several seconds, as if no flash.
Anyone know what setting I need to change?
Thanks

In AV mode the camera tries to expose as if the flash were only there to provide fill. So its behaving normally. Indoors use M mode to control the shutter speed and aperture and let the flash bridge the gap between the 2 settings. I dont have my 40D handy, and I never used the Cfn setting but you can set a safety shift that sets a min shutter speed in AV mode thats faster (maybe 1/200) but its not really AV mode if your SS is fixed.

As gonzo has indicated, AV mode is the problem. In AV mode your camera tries to expose the scene properly by extending the shutter time - as it should in any circumstances - so you get long exposures. I would set the camera to M mode; set the aperture to something like f5.6 so you have good depth of field; set the shutter to about 125th and the flash should expose everything properly. If it doesn't, use some flash compensation as required.

While I would also use M, the setting you need to change is in one of the flash options.

I don't have a 40D but there should be something like 'Shutter Speed with Flash":

1. AUTO
2. AUTO 1/60 - 1/200
3. FIXED 1/200

You have it on 1 when you possibly want it on 2 or 3.

ejenner wrote in post #16294361
While I would also use M, the setting you need to change is in one of the flash options.

I don't have a 40D but there should be something like 'Shutter Speed with Flash":

1. AUTO
2. AUTO 1/60 - 1/200
3. FIXED 1/200

You have it on 1 when you possibly want it on 2 or 3.

Thank you! I knew it was there somewhere, for I have taken many low light flash shots with no problem. I set it on 'fixed' 1/250 and it works well on Av. If needed I can always go to M mode. I don't use automatic mode (just doesn't feel right).

trailguy wrote in post #16294574
Thank you! I knew it was there somewhere, for I have taken many low light flash shots with no problem. I set it on 'fixed' 1/250 and it works well on Av. If needed I can always go to M mode. I don't use automatic mode (just doesn't feel right).

I actually got caught out in the other direction fairly recently - I couldn't figure out why I couldn't get a SS higher than 1/250 (or 1/200) with high speed sync in Av mode. But then I actually use flash more outside in fairly bright conditions with larger apertures than I use it indoors.

Since I use flash in bright conditions a lot I usually have this option set to auto and use M indoors instead. Of course use what works the easiest for you, just be aware that if you go outside with a large aperture you may get over-exposed shots if trying to use flash for fill, even if you try to use high speed sync.