Flash questions!

Precisely why I put "ETTL-II compatible" in quotes. Sigma's designation, not mine.

Maybe they didn't rename it because it's still the exact same unit; only the advertising copy having been changed.

And if most of the improvements went into the cameras WHY is the 580 so bleepin expensive!?!?!? I would love to get a nice flash but to me the 580 is about $150-200 overpriced for what I see are minor updates to the 550. Can someone who knows, educate me on why the 580 is worth the $$?
Sorry, just ranting.

I hear your rant, and I'll raise you one rant. I don't know why it's so expensive, but if I had to guess, I would guess "marketing". Nobody said that it is worth the extra cost. That is a decision for the customer to make.

---Bob Gross---

I don't know how long a flash tube lasts, but I'm sure it lasts a very long time. If it breaks in the end you could even replace it yourself, at least if you feel confident enough to do it.....: http://www.ahomls.com/​550EX/

About having both the 420 and 550: You can use them both at the same time, set the 550 to Master mode and the 420 to Slave mode. This gives you a lot of creative possibilities. For example: http://www.filmlesspho​tos.ca/IndexPage.htm

I didn't say most of the improvements went into the camera. I said E-TTL II was in the camera. Canon upped the GN, speeded recycle time, added colour temerature transmission to compatible cameras, and added sensor-size recognition to the zoom head, all while making the 580EX noticeably smaller than the 550EX.