One of these photos was taken with a high-end Canon 24-70mm "L" series lens costing hundreds and hundreds of dollars. The other photo was taken with a plastic Canon 28-80mm "kit" lens I purchased on eBay, along with a 35mm film camera body, for... and no, I am not making this up... forty cents!
Which is which? (Click through to the full-size version at Flickr if you like; but no fair peeking at the EXIF data!)
NOTE: the light shifted a bit due to cloudy skies. I will have to try this experiment again under more consistent conditions.