Canon ETTL-II users only - Flash question

[pgriz]

@ dylanstraub. First-curtain. I've used second-curtain flash at times, but part of my "housekeeping" is to reset the camera and flashes to "standard" settings as soon as I am finished shooting something, so that if I pick up the equipment, it will be in a known state.

@ Derrel. Yeah. I've considered that. I have a cable that allows me to use the flash off camera while maintaining the E-TTL functionality, and I've noticed that if the attachment isn't perfect, either at the hot-shoe, or at the flash attachment point, things don't work well. But I've not had any issues with the flash directly attached to the hot-shoe, which is why I chose to use this method for testing. However, this possibility means that IF and WHEN I get ETTL bounce failure, the first thing to try is to remove the flash and re-insert it into the hotshoe to establish a good contact and then re-try the shot.

@ Josh: According to the Canon 580EX II manual (pg 29), "C Fn-05-1 (the option to switch to TTL, with option 0 being E-TTL) is geared for EOS-series film cameras. Do not set if you have a EOS DIGITAL camera or the EOS REBEL T2i/300X. If C.Fn-05-1 is set for such cameras, the flash control will not work properly. The flash might not fire or it might fire only at full output." So I have not yet tried how this works, as it appears to effectively disable the TTL functionality. I'm keeping this on the back burner. If my other testing does not give me a reliable protocol to follow when using bounce flash, then I may try this option as well.