Flash for Canon 20D

[AA20D]

Photo-John: good points and advice well considered. However, what you do not know is that I'm also on thin ice with the BOSS right now. I just dropped $1600 for the 20D (kit), now I have to upgrade the flash since my Canon 430 EZ is not compatible for TTL, and to top it off, my beloved 28-105 front focuses with this camera. All other lenses focus fine. So now, I need to consider replacing that lens also or I will have a focal length gap in my system. And I have no desires right now to add a second flash. I can't think of what I may use it for at this time. I've already received the ok to get a small studio strobe system once I have the rest of hte gear paid off. I could sell the BOSS a $300 flash easier than a $480 flash. And besides, I like to bounce flash in my basement since the ceiling is fairly low and that little supplemental flash on the Metz sure looks like it would benefit filling shadows. ;)

[kotya]

It depends how you use the flash unit. I have Metz at the moment and I am going to upgrade to 580EX. Metz (at least the one I have) does not support E-TTL, only TTL which requires manual control every second shot. On the other hand, do not overestimate E-TTL II, it is only uses distance information when aimed directly to the subject, therefore, not distance is used when bounced. How often do you photograph people aiming stright to them?

The white balance information is not that usefull as well, as it will transfer it only when the flash unit detects that the battery going low and therefore the strobe temperature changes. If you use flash with complex lighting or/and as fill flash, it is not going to help. The result will be close to accurate only in flash is your main light.

I would still recommend 580EX over any Metz unit due to the fact that it is really integrated with the camera and it is bi-directional. Not all the E-TTL features supported by Metz due to proprietary Canon E-TTL, they reverse-engeneer and not always 100% correct and not all the features.

In general, if you do not have 550EX, go for 580EX as you will get a bit smaller unit, a bit easier to use controls on the back and a bit faster recycle and a bit more powerfull output. So, there are quite a few "bits" that make 580EX better flash vs 550EX, but there are no "wow" that will force 550EX users to run to a shop to upgrade.

[jwyatt]

I don't suppose a 540EZ can be used as a slave for a 580, can it? I' have a 540EZ on my EOS 50E and have just bought a 20D and 580EX, so it would be handy...