I was taking some pictures of my daughter against the wall at night, under incandescent lamp, using flash.
In Av mode, with aperture at 4.5, the image was very dull. But if I upped the flash power to next step, it would be too much. It was taking ISO (set on Auto) as 1600.
Then I put it on P mode and the same picture was much brighter, though colors a bit "dynamic" rather than natural. The aperture was 4.5 but ISO was 640.
My question is, why this difference? If I set aperture @ 4.5 in Av, why is the ISO and final result so different.
Also, in Av mode, the flash power has only 3 steps and default seems to be least, whereas in P mode flash power has 12 steps from -2 to 2.