这是个笼统的比喻。具体点说

来源: 于 2012-01-31 09:25:57 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

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