Mark Cassino has the Sigma, I have the Pentax. We did an impromptu and very unscientific comparison at a Michigan PDML gathering a couple of years ago. At f2.8 and f8 at about 50' distance, at 200mm, the Pentax was sharper. And, Mark states the Sigma freezes wide open at temps below 5 degrees.
Ryan wrote: PS. Always wondered how accurate photodo ratings are.. the FA*80-200 2.8 didn't match up to Sigma's EX 70-200 2.8.. Anyone?
