http://www.naturalart.ca/artist/fieldtests/500mmwars_sigma_nikon.html#500mm_wars_8

评测里说和尼康500/4比，画质一样，不相上下。
调焦以后(原厂和适马都需要微调)对焦速度和合焦准确率胜过原厂。

When these trials were performed using 72-point dynamic area focusing on a D5 the Sigma Sport 500mm f4 produced an overall "keeper" rate of 90.2% of the shots, with a full 50.5% of the shots being judged as very sharp. When using 72-point dynamic area focusing on the D5 with the Nikkor 500mm f4E I obtained a keeper rate of 87.1%, with 41.8% of the shots being very sharp. When I switched to 9-point dynamic area focusing I found the same overall trend, with the Sigma 500 very slightly out-performing the Nikkor 500 in both keeper rates and percentage of sharp shots. In these 9-point trials the Sigma 500 produced a keeper rate of 88.7% with 49.3% of the shots being very sharp. In 9-point dynamic area mode the Nikkor 500 produced keeper rates of 84.9% with 36.0% of the shots categorized as very sharp.

72点对焦
适马 90.2%合焦、50.5%非常合焦
原厂 87.1%合焦、41.8%非常合焦

9点对焦
适马 88.7%合焦、49.3%非常合焦
原厂 84.9%合焦、36.0%非常合焦
本帖最后由 kirbyzhou 于 2017-3-27 18:30 编辑

不知道能不能加佳能原厂增距镜

应该学佳能。把1.4X集成进去，能多卖$1000呢。

好长的文章！

从对比上看SIGMA 500/4真的不错。如果价格再下来点就更好了！