Why won't the D600 have better high ISO performance than D800?

Started Sep 13, 2012 | Discussions thread
Luke Kaven
Veteran MemberPosts: 4,988
Like?
Re: don't larger pixels grab more light?
In reply to Dan, Sep 14, 2012

Dan wrote:

Let's say we have a 1pixel sensor vs. a 100pixel sensor. The pixels of the 1 pixel sensor obviously get more light because they are 100 times bigger, getting that much more light.

Noise is measured per unit area of the sensor . Having 4 pixels in the space of one pixel actually confers some noise improvements.

The best explanation of this is in Emil Martinec's papers on noise calculation.
http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/noise-p3.html#pixelsize

"The raw value is proportional to the number of photons collected; combining pixels, the photon counts add and so the raw values should be added together:

S = S1 + S2 + S3 + S4

The noises combine in quadrature:

N = sqrt[ (N1)2+(N2)2 +(N3)2+(N4)2 ]

If the raw values are approximately equal, and the noise contributions are approximately equal, the aggregate signal is four times that of the individual pixel; on the other hand, the aggregate noise is about twice the noise of the individual pixel. Thus the "superpixel" of four pixels binned together has twice the S/N ratio of any of its component pixels."

Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow