[pongyee]

我幾年前在雜誌看過話過億。

[pongyee]

係呀，所以幾年前我唔睇好數碼相機，以為佢有排都追唔上。

但係後來話135底片係在最好狀態下才過億，200度又會少 d，曝光不足或過度又少 d。而數碼就乜情況下都一樣咁多像素。

[man1492]

麻甩佬一次都過億，你又睇唔睇到?

[呀超]

益力多？？？

[derek2000lau]

過億??????
有什麼理論呢??

[pongyee]

>>有什麼理論呢??

那不是理論，是計算化學顆粒的大小而得出的。

[Obi-Wan]

an ideal lens used in 35mm FF DSLR always has a resolution 2000 lines per inch for B & W film
doglun

1 inch = 2.54 cm = 25.4 mm
1 mm = 1/25.4 inch => 2000/25.4 lines = 78.74 lines assumed to be 78.74 dots

FF film = 24mm X 36mm = 24 X 36 X (78.4)2 = 5,310627 dots

BUT for colour CCD (except those used in SIGMA), the CCD array GGRB arrangement.
the actual resolution is much less, 10 MP CCD is in fact equivalent to 2.5 MP dots.

THEREFORE IN ORDER TO GET THE SAME RESOLUTION OF A FF FILM, THERE SHOULD BE

4 X (5,310627) = 21,242,511 pixels

> 2000萬

[Carl Zony]

二千萬像素可唔可以放到大戲院銀幕呢?

[Carl Zony]

電視....35mm....?唔多明?我淨係知電影用緊半格135 o炸!同埋以前d戲院好大間,個銀幕大過e家d細戲院,唔知一個大銀幕要幾多萬像素呢?

[hsc]

咁多像又點呢?
支鏡又要頂得順先得嫁

[Obi-Wan]

hsc, "支鏡又要頂得順先得嫁"

before 1940, the German lens makers could easily achieve lens with > 3000 lines per inch resolution (for BW or IR film) or > 4000 lines per inch for aerophotos (optimized for monochromatic light & at 0 to 5 °C)

but for colour film, the lens resolution seldom excess 2500 lines per inch.

Today, most lens makers can easily make lens with > 1500 lines per inch in the middle, which is equivalent to 13MP CCD resolution

[foto_man]

對這問題有興趣的也可看看這網頁http://www.normankoren.com/Tutorials/MTF7.html