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

Sigma 400 mm f/ 5.6 APO used:

NameFull namePlaceScoresRank
1stephen marmaroff 51.2lvl.1 (Lens-Learner)
2Sean TengSean Teng SeanTaipei571.951lvl.3 (Lens-Competent)