http://www.lenstip.com/243.11-Le ... .5-5.6_Summary.html
Pros:
very good image quality in the 80-300 mm range,
negligible chromatic aberration at 80 mm focal length,
low distortion level,
well-controlled coma,
very low vignetting,
satisfactory work of autofocus,
solid casing and high build quality,
small dimensions for such a wide focal length range,
tripod collar and lens hood included.
Cons:
weak image quality at 400 mm,
huge chromatic aberration in the 300-400 mm range,
minimum focus from as far as 2.5 meters,
distinct astigmatism at longer focal lengths.
80300時好正
400時"質素"很差，300以上嚴重偏色，要成2.5m對焦
