A Great Article On Lens Variation

The owner of Lens Rentals, which has a great logo, has posted an enormously enlightening article over at DPReview. He discusses variation in lenses and cameras, revealing differences to a degree that I didn't know was possible. He argues that trying to find a "good" example of any given lens is pointless, but the fact that some of the lenses he shows have variation wide enough where the lowest-quality example is significantly below the highest-quality example.

The most important take-away for me is the realization that lens reviews, especially those where two lenses produce very similar results, must be taken with a grain of salt.