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

SIGMA AF 50-500 mm f/ 4-6.3 APO HSM EX DG RF used:

NameFull namePlaceScoresRank
1iv 71.2lvl.1 (Lens-Learner)
2kasak57 AlexanderKrasnoyarsk156.95lvl.2 (Lens-Adept)
3Bill Ray Bill RayTulsa7.5lvl.1 (Lens-Learner)