这是个笼统的比喻。具体点说

1. If the diffraction limited spot size is 1um, your lens has a spot size of 3um, that is 3 times bigger, or in anoother term, 1/3 of the best.

2. If the diffraction limited MTF allows 0.8, your lens has 0.2, that is 25 of 100

所有跟帖： 

• Distortion is also important -二泉映月09- ♂ (202 bytes) () 01/31/2012 postreply 09:29:26

• 正想说这个 -云漫- ♂ (858 bytes) () 01/31/2012 postreply 09:44:53

• 是。民用也用不着很好的。 -二泉映月09- ♂ (0 bytes) () 01/31/2012 postreply 10:00:08

• 云师分析的一个通俗例子: 军队的战地记者用的是民用镜头. -河舟- ♂ (0 bytes) () 01/31/2012 postreply 11:08:46

• 谢谢，相信军品和民品之间的差距，光是民品，不同的品牌，就差得很大。 -河舟- ♂ (0 bytes) () 01/31/2012 postreply 09:35:54

• 是的。我看到过一个名牌变焦镜头在有些地方MTF=0，忘了哪个牌子. -二泉映月09- ♂ (0 bytes) () 01/31/2012 postreply 09:40:49