D800E的分辨率

Thom大嬸又開始發燒胡說了。哦,不對,他也是抄的。意思就是買個800E就可以體驗一下間諜衛星在軌分辨率高於一米是啥樣子的了。

拿低端民品開軍品的玩笑這還是頭一朝。

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How Good is the Q?
Feb 8 (commentary)--I'm going to let someone else do the talking:

"I’ve spent the past 45 years involved in the analysis and design trades of spaceborne imaging systems (like the earth viewing Geoeye-1 telescope in orbit today), and Q is a wonderful, insightful and useful parameter. Q can be shown to be equal to wavelength x fno / pixel pitch. If we ignore the use of Bayer filtered pixels and do the calculation on a monochromatic basis (without a de-aliasing filter), for a Q=2 D800E (fully satisfying the Nyquist criterion at 0.55 microns), the fno turns out to be f/17.7. Thus an f/8.9 lens aperture setting on the D800E gives you a Q=1 system, which makes the D800E equivalent from a sampling standpoint to the Geoeye-1 telescope (which has a Q=0.95). In fact, many spaceborne imagers are about Q=1, which has turned out over the years to be a good compromise between resolution (NIIRS, if you are familiar with the government image quality measure) and low light performance (i.e. , SNR). And it’s interesting to note that the use of a lens set at f/8 (often the aperture that delivers the best quality image – i.e., best MTF) dovetails nicely with the achievement of a Q=1 D800E imaging camera. 
 
So one could consider theD800E, at f/8, to be a miniature Geoeye-1 telescopic camera. The D800E has hit the traditional sweet spot for earth imaging satellite systems!"

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GeoEye-1的分辨率數字

Imaging & Collection Specifications

Launch Date September 6, 2008

Camera Modes
  • Simultaneous panchromatic and multispectral (pan-sharpened)
  • Panchromatic only
  • Multispectral only

 

Resolution 0.41 m / 1.34 ft* panchromatic (nominal at Nadir) 
1.65 m / 5.41 ft* multispectral (nominal at Nadir)

所有跟帖: 

不明白他在說什麽 -雲漫- 給 雲漫 發送悄悄話 雲漫 的博客首頁 (155 bytes) () 02/09/2012 postreply 08:07:57

早會聽prez無聊時上網看到的。你是對的。整體係統裏機光電分係統裏,機電不再是障礙 -U96- 給 U96 發送悄悄話 U96 的博客首頁 (89 bytes) () 02/09/2012 postreply 08:21:11

兩眼一麻黑, 沒法Q了 -吳聚- 給 吳聚 發送悄悄話 吳聚 的博客首頁 (0 bytes) () 02/09/2012 postreply 09:07:43

老U看來是長草了,自打D800出來後, 不僅尼康粉 -天逸- 給 天逸 發送悄悄話 天逸 的博客首頁 (55 bytes) () 02/09/2012 postreply 09:35:01

沒長草,按自己的計劃來,不想拉人下水 -U96- 給 U96 發送悄悄話 U96 的博客首頁 (311 bytes) () 02/09/2012 postreply 09:48:42

老U玩起棚拍和NEX了,不過無論 -天逸- 給 天逸 發送悄悄話 天逸 的博客首頁 (154 bytes) () 02/09/2012 postreply 10:41:43

提醒一下Nex新一代用的是D7000水平的CMOS -U96- 給 U96 發送悄悄話 U96 的博客首頁 (212 bytes) () 02/09/2012 postreply 10:47:42

Nex5N確實不錯,不過,要考慮到用另一套鏡頭係統就很麻煩了 -天逸- 給 天逸 發送悄悄話 天逸 的博客首頁 (202 bytes) () 02/09/2012 postreply 11:39:22

nex接環加peaking不用另配一套係統 -U96- 給 U96 發送悄悄話 U96 的博客首頁 (82 bytes) () 02/09/2012 postreply 11:55:10

可是對焦還得手動吧,老了,還是自動吧 -天逸- 給 天逸 發送悄悄話 天逸 的博客首頁 (0 bytes) () 02/09/2012 postreply 12:02:22

旁聽你們的討論, -空心竹- 給 空心竹 發送悄悄話 空心竹 的博客首頁 (50 bytes) () 02/09/2012 postreply 12:04:35

1係列還是另一套鏡頭。加自動接環可以用AF,不過暗光性能soso -U96- 給 U96 發送悄悄話 U96 的博客首頁 (75 bytes) () 02/09/2012 postreply 12:41:49

一半同意老u的觀點,不會太快,4-5年吧 -大大仙- 給 大大仙 發送悄悄話 大大仙 的博客首頁 (0 bytes) () 02/09/2012 postreply 12:06:56

器材壽命+觀念慣性。但感覺現在觀念慣性比膠片進入數字時代小得多 -U96- 給 U96 發送悄悄話 U96 的博客首頁 (304 bytes) () 02/09/2012 postreply 12:47:26

天兄有錢樹,進 D4 + D800E 的了! -enTiger744- 給 enTiger744 發送悄悄話 enTiger744 的博客首頁 (0 bytes) () 02/09/2012 postreply 12:00:41

嗬嗬。我也想進D4, 還是太貴了,而且一個全福和一個半幅比較好match -天逸- 給 天逸 發送悄悄話 天逸 的博客首頁 (0 bytes) () 02/09/2012 postreply 12:04:46

純理論的, 看不懂啊! -Alabama- 給 Alabama 發送悄悄話 Alabama 的博客首頁 (0 bytes) () 02/09/2012 postreply 10:27:11

嗬嗬, 老U是見著新器材就真睡不著覺了。。。 -enTiger744- 給 enTiger744 發送悄悄話 enTiger744 的博客首頁 (0 bytes) () 02/09/2012 postreply 11:54:32

:-) 興奮點嘛 -U96- 給 U96 發送悄悄話 U96 的博客首頁 (0 bytes) () 02/09/2012 postreply 11:58:54

等U班的好作品了,特別是棚拍哈,新領域,更刺激 -akuan- 給 akuan 發送悄悄話 (0 bytes) () 02/09/2012 postreply 22:55:20

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