Hmm? What? Were we talking about an XT? []


I dunno if this site can be trusted, but they list tons of stats:


http://www.dxomark.com/index.php/eng/Image-Quality-Database/Canon


The 30D has a low-light iso score of 736. The XT has a score of 637. This number is the highest ISO possible before the signal noise ratio goes above some threshhold. (So, ISO 736 on the D30 is like ISO 637 on the rebel). That's a fraction of a stop. I doubt anyone would notice the difference in normal use.


These guys also have an "overall stat" which I don't trust at all because I couldn't find out what it meant. But it is supposed to take into account noise, dynamic range, color depth, and resolution and who knows what else. On this stat, the XT actually scores ever so slightly higher than the 30D (59.9 to 59.5... they say 15 points is a single stop, whatever that means when you're taking all that stuff together into account, but anyway, no difference at all in practice).


Of course the 30D has other advantages over the rebel (if you care about low light, you might care that the 30D can focus in lower light), but I wouldn't switch for low iso performance.