Found this great
link which basically explains everyting there is to know about flash fotography with canon EOS cameras. Page 2 is especially recommended. Heaps better than canon's manuals.
Two things that comes to my mind that arent't 100% clear and perhaps some of you flash experts might tell me:
1 In ETTL II can you still autofocus on your subject and then re-compose to take a shot without effecting the flash exposure?? Flash metering systems are biased towards the focusing point in TTL and ETTL, wonder if any of you have done some expertiments there??
2 Also for my non-flash photography i use the centre focus point and centre weighted average for exposure. In flash photography the camera's exposure metering meters for the background whereas the flash does the foreground/subject. Will I still be able to use that or am i best to switch to evaluative (on the camera, as the flash metering is evaluative for ETTL2) and automatic focus point selection?