Luminous Landscape Forum
Site & Board Matters => About This Site => Topic started by: BernardLanguillier on July 22, 2009, 05:20:17 pm
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Hello Nathan,
Interesting read.
One question though, the larger the amount of pixels in a given surface, the smaller the photo-receptive surface, right (assuming that we are already pretty optimized there)?
Aren't we going to run into another wall which is the amount of photons hitting the photo-receptive surface during a short exposure? Since light is essentially a discrete quantity, the amount of photons is in fact directly related to the amount of steps that can be discretized, and therefore essentially to the bit depth, correct?
With 100Mp sensors, will we still be able to get 14 real bits?
Cheers,
Bernard
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Hello Nathan,
Interesting read.
One question though, the larger the amount of pixels in a given surface, the smaller the photo-receptive surface, right (assuming that we are already pretty optimized there)?
Aren't we going to run into another wall which is the amount of photons hitting the photo-receptive surface during a short exposure? Since light is essentially a discrete quantity, the amount of photons is in fact directly related to the amount of steps that can be discretized, and therefore essentially to the bit depth, correct?
With 100Mp sensors, will we still be able to get 14 real bits?
Cheers,
Bernard
I'm not sure we really get 14 bits of data now, though that's mre about noise than lack of photons at low isos
Mike
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One question though, the larger the amount of pixels in a given surface, the smaller the photo-receptive surface, right (assuming that we are already pretty optimized there)?
Aren't we going to run into another wall which is the amount of photons hitting the photo-receptive surface during a short exposure? Since light is essentially a discrete quantity, the amount of photons is in fact directly related to the amount of steps that can be discretized, and therefore essentially to the bit depth, correct?
I think there are two aspects of this problem. One is that all pixel boundaries will loose photons so when you increase resolution you will at one point have a sensor that only consists of pixel boundaries and no more is able to record any light. The other is that higher resolution sensors will have to cope with the same number of photons but will be able to record their position more accurately. This is of no use any more though when the pixels are so small that a significant number of them does not receive any photons at all (and the usefulness of the additional pixels rapidly decreases with photon count per pixel approaching zero).
But of course there are many situations where sufficient light is available to still decrease pixel sizes quite a lot. This would mean lower sensitivity sensors of course.
Greetings,
Christoph
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Interesting prospect - marketing having to think up a new 'feature' to push. Perhaps time to see 'digital zoom' reintroduced :-)
But seriously, I had a lengthy technical paper on this issue published several weeks ago by David Goldstein, on the Northlight Images site. The article itself misses out most of the maths, but there is a full version available as a PDF download.
If you read it, do check the comments, since David has informed me he's working on an update to the article that clarifies a few points covered in those comments.
Physical limits in digital photography (http://www.northlight-images.co.uk/article_pages/guest/physical_limits.html)
hope it helps clarify things :-)