Quote Originally Posted by benjiboy View Post
but reading through this thread it makes me wonder how much variation there can be between different lenses of the same focal length and aperture and if my 24mm f2 is giving the same performance as yours, and how valid these comparisons are after about twenty five years since they were manufactured
Just reading through this thread for curiosity (very little experience with Canon FD lenses).

But in general, nothing should be wrong with a 25 year old lens, unless it's picked up haze, fungus or has been physically damaged (or are Canon lenses so delicate that they wear out so quckly.. )

General observation on wides: if you have and use a 50mm, a 28mm is a classic first wide.
I prefer a 35mm as a normal, so my wides are 24mm or 19/20/21mm.

A cheap but very good ultrawide is the Vivitar/Tokina 17mm (usually much better than the equivalent Tamron, but apparently with lots of sample variation, with the Vivitar branded ones doing better), but I'd only consider that after one of the focal lengths mentioned above.