Question on flash in AV mode

[Vic_izoita]

Hey all,
I usually shoot in P mode with my 2 month old 10D due to lack of knowledge and now im trying to play with AV.
Here is the problem that im having: Say I set my camera to AV and and set the aperture to f8(the lens is 24-85mm USM). Im trying this indoors with ok lighting, cloudy, 10am with windows opened. With having my ex420 off I half press the shutter and the camera will choose 4 for shutter speed. Then if I turn my flash on and not change anything else when I half press the shutter the camera still selects 4 for shutter speed.
My expectation was that with flash on I would get much highter shutter speed number. The same results if i try this test with the builtin popup flash.In my custom functions the “ flash sync speed in AV mode” is set to default which is “Auto”..
Any feedback would be greatly appreciated.
Thanks
Victor

[drisley]

That's normal.

Read the question I posted when I got my 300d

http://photography-on-the.net/forum/showthread.php?t=23398&highlight=

[Jesper]

In Av mode with flash, the camera will set the exposure to capture ambient light - so you'll get a slow shutter speed if there is little ambient light. See page 97 of the manual.

If you don't want automatic slow sync flash but you do want to control the aperture, use M mode and set the shutter speed to 1/200s or slower.

[yenoram]

Read the following article on the Canon flash system. This is the best info I've come across and I learned a lot in the process.

http://photonotes.org/articles/eos-flash/

[Vic_izoita]

Thanks for your answers guys. Yenoram, i apreciate the link... Great article.
Victor