All About Photographic Lenses.
Specifications, comparison, reviews, MTF-charts for lenses by Canon, Nikon, Sony, Pentax, Olympus, Sigma, Tamron, Carl Zeiss, etc.

Sigma 28-70 mm f/ 2.8 used:

NameFull namePlaceScoresRank
1Sean TengSean Teng SeanTaipei571.951lvl.3 (Lens-Competent)