回复：回复：是这样测试的...

我两张都用的新头，手持. By looking at the first image, the lens already shows very good sharpness under the 手持, F4 and 1/10 second condition.

你用什么相机测的？D200

测３５时距离是多少？about 35 feet. This

用这个头拍要虚化背景是不是有点难（光圈不够大）？是有点难.

你测试的五张卡贴的位置亮度不同，对结果有影响吗？ Not at all. We are looking at the sharpness. Besides, I used single center focus.