如题，谢谢！

给个网站直接算吧.
http://www.dpreview.com/learn/?/Glossary/Optical/Depth_of_Field_01.htm

谢谢版主，不过看不了呀，能给个具体公式吗？
An Error of the type "Server object" has occurred

There is no need to contact us about this error as we are already aware. This is for information only.
Regards
The www.dpreview.com Web Master

Error Number -2147467259
Error Code ASP 0175
Error Description Disallowed Path Characters
ASP Description The '..' characters are not allowed in the Path parameter for the MapPath method.
Category Server object
File Name /learn/Default.asp
Line Number 152
Column -1
Error Source

Provider error '80020005'

Type mismatch.

/misc/errorhandler.asp, line 466

那个连接没问题, 你等回再试.
景深计算不止一个公式, 我想也没有必要自己算, 公式下面有:

http://www.arteast.cn/Photography/syjc/syjc-7.asp

谢谢版主！