Pamela;


I'm in the same boat...40D and eventually wanting to upgrade to a FF body and keeping the 40D as a back up.


After a couple of years of circling the EF-S lens and L lens conundrum, I've come to the conclusion of buying the lens that best suits my needs using the 40D today.


I currently own the 17-55 2.8 IS (traded in my 17-85, specifically for the fixed 2.8) and the 100-400 IS lenses for my landscape, indoor family gatherings and wildlife shootings.


I've also used both these lenses for indoor high school sports, e.g. volleyball and swimming w/very suitable results.


I am now venturing into Real Estate photography (just sold my first shoot the other day) and will purchase the 10-22 in the next few weeks to help w/the tighter shots and expand my landscape shots.


My point of this diatribe is; buy for today's needs (wants) and allow your (future) sales to buy the (really expensive) FF body and lenses for your kit.


My next (priority) purchases will be the 70-200 2.8 IS (low light Hummingbird shots), 100 Macro, and finally the FF body. And if after purchasing the FF, I find it necessary, I will then purchase the 16-35 2.8.


Just my game plan (opinion) for buying equipment I can't afford to buy all at once.


Two final thoughts; remember IS is for low light, relatively static
subject, situations. IS will not stop a subjects movement, i.e. "to
catch children in action/sports". Secondly, the 40D isn't weather (wx)
sealed, so don't become overly concerned about lenses that are...wx
sealed lenses won't help your 40D to stand up to inclement conditions.


Good luck and frequent this site's reviews of the equipment you want.....often.


Regards


Bill