Well i have just acquired a 1d mk2. And i also have a 40d.
My current lens line up is.
Tokina 11-16mm f2.8
Sigma 18-50mm f2.8
Canon 50mm f1.8
Canon 70-200 f4
C
urrently the only usable lens i have for the 1d is the 70-200. So i am looking to sell the sigma and replace it with something that will be suitable for both the 1d and the 40d.
The 17-40 was my instant reaction simply because it as affordable as you say.
It will be fine on the 40d, but i am thinking it might be a bit too wide on the 1d.
I am looking for a
general walkabout lens, but i would also like it to be suitable for portraiture, which is why i am thinking the 17-40 would be too wide.
F2.8 would be nice, but not absolutely essential i don't think.
The other two options i guess are the
24-70 and the 24-105.
I'm not sure what their
second hand values are like, but i believe it is quite a step up from the 17-40.