I'm so confused!

A friend and I were shooting birds yesterday, around a backyard feeder. We both shoot a 50D with a 100-400L lens. He was using a 430 EX and I was using a 430 EXII. It was a flat gray and dull sky. He was shooting his flash in ETTL at full power. His pictures at 30 -40 feet came out well exposed. This blows me away. As I assumed, there was no return detected, due to the angle and the empty area around the bird. When I attempted that, the flash blew the heck out of everything. Also, we were both shooting at 5.6 and 1/250 sec. The only difference is, his shots were at ISO 400 and mine at ISO 640. When I attempted to shoot the flash in manual, even at 1/64 power, it was over powering. Any explanation or advice?

mn shutterbug wrote in post #9235421
He was shooting his flash in ETTL at full power.

This doesn't make sense. In E-TTL mode, the camera decides how much power to use.

When using Manual flash mode, use the distance scale on the back of the flash to help with power adjustments. If it's giving you too much light at the lowest power setting, you need to stop down the aperture or lower the ISO.

I agree, it doesn't make sense. Since there was no return detection, the flash should have stayed on way too long.

What do you mean, there was no return detection?

Were you both shooting with the camera in manual mode? If so, your pictures might have been overexposing because of the higher ISO you were using. In other words, the overexposure might have been from the ambient lighting rather than the flash. Did you check the meter in the viewfinder to see if the camera settings were appropriate for the ambient exposure you wanted?

Leo, we were both shooting in Av and his was set at +1 EC, which should have made things even worse, whereas mine was set at +2/3 EC.

I should clarify one thing. We compared his shots from yesterday and mine from today. This is why he was shooting at ISO 400 and me at ISO 640, and getting the same shutter speed and aperture.

It's all been figured out. The problem was me. I haven't advanced with technology. My mind was still back in the 80's with the old technology.