Help troubleshooting a 430ex shooting at full power

[quachro]

Has anyone had this problem? My 430ex I is firing at full power all the time. I've tried on camera ETTL and manual @1/64 power. No matter what setting I use, it seems like the strobe is firing at full power all the time. Thanks in advance.

[symby]

Checked your settings on the flash itself?

[quachro]

Yup, I changed the setting on the flash itself.

[symby]

What other settings are you using? I'm still working out using my 430ex but I suppose its possible that due to your other camera settings 1/64 of the power needed is still full power. I could be way off on that one though.

Have you tried setting your Flash Exposure Compensation while in ETTL mode as well to see if that tones down the flash?

[quachro]

I have tried ETTL -3 and Manual mode at 1/64 of a power. Both result in a full power fire. At 1/64 power and camera setting: iso100, f/8, 1/125, it would super underexpose the picture.

[symby]

At 1/64 power, iso100, f/8 and 1/125 shutter its underexposed? Even if the flash its supposedly firing at full power? Still sounds like 1/64 of the power needed is the full power the flash can put out (haven't confirmed if thats possible to happen). Are you expecting too much from the flash? What kind of lighting conditions are you shooting under? How far is your subject?

[quachro]

With that camera setting, you would expect the picture to be well underexposed, but its not. It is actually overexposed at little. I'm expecting in a low light condition the flash would underexpose if it is set to 1/64 power and with my camera settings. I don't think my problem is the camera settings. The reason I say that is because I have shot 6 shots with different flash output power and keeping the camera setting the same. Camera and flash is both in manual mode. I went from 1/64, 1/32, 1/16/, 1/8, 1/4, and 1/2 on the flash and all of the shot have the same exposure. 1/64 and 1/2 look the same. One would expect 1/64 to be well underexposed.

[40Dude6aedyk]

I seem to recall more than one thread where a 580EX always flashed at full power until it was sent in to be repaired. This does not appear to be an uncommon occurrence. You can even look below at "Similar Threads".