same happens to me, gkw12345. I own the same flash and seems that combined with my EOS450d and any of my lenses, photograps are underexposed when using AUTO or TTL modes of the flash. And I have absolutely no idea what the reason can be. I've even tried e-mailing the company but the answer had...
Hi there, I'm having problems with my Nissin di866 mounted in my EOS450d. Every time a try to take a photo, setting AUTO mode on my flash, each photo seems to be terribly underexposed. The opposite happens afer setting the flash to manual mode: every shot is overesposed.
Does anyone know why...