Same

来源: pieq314 于 2007-02-22 10:09:52 [] [博客] [旧帖] [给我悄悄话] 阅读数 : (397 bytes)
回答: 回复：涌流在吗，问个问题 由 pieq314 于 2007-02-22 09:23:55

If you superimpose 5 photos with each exposed at 6 sec, you will get the same result in noise as one photo with 30 sec exposure (assuming everything else being the same). I posted a few posts a few days ago that explained that noise is proportional to 1/sqrt(signal). So if total signal is the same, noise will be the same.

U96 pointed out one situation when some thing else is different.

所有跟帖： 

• interesting, but it would not be the same if ur formula is right -lilywxc- ♀ 给 lilywxc 发送悄悄话 (156 bytes) () 02/22/2007 postreply 10:20:29

• You need to add signals first. -pieq314- ♀ 给 pieq314 发送悄悄话 pieq314 的博客首页 (235 bytes) () 02/22/2007 postreply 10:38:53

• numbers? -lilywxc- ♀ 给 lilywxc 发送悄悄话 (281 bytes) () 02/22/2007 postreply 10:48:08

• Noise is random. -pieq314- ♀ 给 pieq314 发送悄悄话 pieq314 的博客首页 (341 bytes) () 02/22/2007 postreply 11:06:46

• i see, thanks! -lilywxc- ♀ 给 lilywxc 发送悄悄话 (0 bytes) () 02/22/2007 postreply 11:08:40

• 回复：Noise is random. -Arakis- ♂ 给 Arakis 发送悄悄话 (422 bytes) () 02/22/2007 postreply 14:14:59

• Yes -pieq314- ♀ 给 pieq314 发送悄悄话 pieq314 的博客首页 (707 bytes) () 02/22/2007 postreply 14:50:01

• 回复：Same -Arakis- ♂ 给 Arakis 发送悄悄话 (422 bytes) () 02/22/2007 postreply 14:23:24

• 回复：Same -Arakis- ♂ 给 Arakis 发送悄悄话 (210 bytes) () 02/22/2007 postreply 14:30:35

• This is another case where "everything else" is not the same -pieq314- ♀ 给 pieq314 发送悄悄话 pieq314 的博客首页 (240 bytes) () 02/22/2007 postreply 15:10:57

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