Quote Originally Posted by Mark Elberson
What I'd like to see is two pictures taken with lenses having different amounts of barrel distortion but in the example itself having zero perspective distortion. If you get bored maybe you could show us since I "think" you have two lenses that would apply

Yep, the 24-105mm @ 24mm vs. the TS-E 24mm which is about as undistorted as you'll find at that focal length. The only examples I have of the same scene shot with both are where the TS-E corrects for both (perspective corrected with shift), but I'll find a bit of time to shoot a straight-on comparison which will isolate the barrel distortion component in a 'real world' setting.