Hello,
I just bought a Speedlite 580EX II. When I used it on my 50D, I notice it will emit a sound when auto zoom function is modifying the distance information. When auto zoom is not functioning, the flash is very quiet. Is this sound normal? Or I have unlucky enough to get a mulfunction unit?
Also, I notice that when I switch to Av mode with the flash on my camera, I will always see a blinking "60" for the shutter speed from view finder. Why is it blinking all the time? Regardless of the aperture and the ambient lighting, it is fixed to 60 and blinking.