Settings for flash shots

[miniman]

Slightly confused about how to set up the camera for the best flash shots. If it is left in Av or Tv mode, it doesn't seem to compensate for the fact that the flash is switched on. For example, with the flash off, the metering might give 1/60 f/3.5 - if I then switch the flash on, it sets the same exposure. Does it not know that there is going to be more light from the flash?

I have taken to setting it to 1/200 f/5.6 or f/8 ISO 200 (this is 40D + 430EXII) - the results seem ok, but I usually have to dial in some -ve flash comp to get rid of some glare.

Not entirely convinced I'm doing this right...

[SamHH]

The camera will use the flash in different ways depending on the exposure mode selected and the ambient light. See here for details:
http://photonotes.org/articles/eos-flash/index2.ht...

A very brief and simplified explanation is that in Av and Tv modes the camera will set the other variable (i.e. shutter speed and aperture respectively) to correctly expose the background which the flash will not be able to illuminate.

Does this help you?

[miniman]

Yeah that does help, thanks. What I hadn't grasped was that the camera is trying to set the exposure for the background, not the foreground.

[DIW35]

I usually set my camera to Tv and the maximum allowed flash sync speed, somewhere aroun 1/200s on my 40D. The camera then takes care of the aperture and flash output for a correct exposure.