Canon AV mode flash sync speed


Status
Not open for further replies.

teck21

New Member
Nov 16, 2007
103
0
0
Hi all,

i have some question regarding the sync speed for my canon 450D.
Whenever i set to <P> mode or auto mode with my flash activated, my shutter speed would be 1/60 with f2.8 but when i set the camera mode from <p> mode to AV mode, the shutter speed would be ~1sec althought the aperture remains at f2.8. I had set AV in C.fn to auto. iissit suppose for canon camera to work in this way cos i heard from my fren that for nikon the shutter speed will be sync with the flash when the mode is set to aperture priority. Thanks newbie here...

:confused:
 

Hi all,

i have some question regarding the sync speed for my canon 450D.
Whenever i set to <P> mode or auto mode with my flash activated, my shutter speed would be 1/60 with f2.8 but when i set the camera mode from <p> mode to AV mode, the shutter speed would be ~1sec althought the aperture remains at f2.8. I had set AV in C.fn to auto. iissit suppose for canon camera to work in this way cos i heard from my fren that for nikon the shutter speed will be sync with the flash when the mode is set to aperture priority. Thanks newbie here...

:confused:

Here's a good source of information on the Canon EOS flash system, http://photonotes.org/articles/eos-flash/
 

Increase ISO speed to achieve handholding speed. In low light, Av mode reduces ambient exposure by 1 stop when flash is used.
 

Increase ISO speed to achieve handholding speed. In low light, Av mode reduces ambient exposure by 1 stop when flash is used.

How much do you want to increase from 1s to handhold speed of let's say 1/30sec? If you start with 1 sec at ISO 100 you'll get ISO 3200 for 1/30s. Not sure if such a noisy image is what TS wants to achieve.
Better read the documentation behind the link. The metering mode here is also important to determine which part of the image is used for the exposure metering. Finally, the exposure meter doesn't need to show 0EV when flash is used. One can get good images with -2EV and FEC at +1. Can be done in Av or M.
 

Status
Not open for further replies.