Canon’s Testing a 75MP+ Pro DSLR

Started Jul 21, 2013 | Discussions thread
AndreaV
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Re: Just in time......
In reply to bobn2, Jul 29, 2013

Bobn2 wrote:

AndreaV wrote:

Canon's bottleneck to DR is pixel DR, so the only way to get more DR is to have more pixels. A 1MP FF Canon DSLR would have horrendous image DR.

Sorry... how you relate the fact of having more pixel (then smaller ones, I suppose), to higher dynamic range?? From physics I would expect larger pixels = better dynamic range...

I wonder which physics you are thinking about? I can't think of many if any physics results that would suggest more DR for fewer, bigger pixels - but I do know engineering reasons (based on Physics) which more, smaller pixels will result in better dynamic range. The DR of a pixel is in theory invariant under 2D scaling - in practice it gets a little worse as you scale down in the same technology, but has hikes upwards as new technologies kick in, enabled by the smaller scales. Intrinsically, the same size sensor pixels with the same DR, overall DR goes up as the square root of the number of pixels. The pixels don't quite maintain the same DR but in practice they retain more than enough to endow sensors with more pixels with more DR.

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Bob

Well, I can't quite understand your argumentation, but looks like that also in Stanford University and TU Delft they agree with me:

http://isl.stanford.edu/groups/elgamal/abbas_publications/C072.pdf

"DR increases roughly as the square root of pixel size, since both C and reset noise (kTC) increase approximately linearly with pixel size. SNR also increases roughly as the square root of pixel size since the RMS shot noise increases as the square root of the signal. These curves demonstrate the advantages of choosing a large pixel"

http://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDIQFjAB&url=http%3A%2F%2Frepository.tudelft.nl%2Fassets%2Fuuid%3A2f31c7c5-5019-4cab-a9c5-65528f886a76%2Fwang_20081103.pdf&ei=XmT2UbTLBcPwOomJgcgB&usg=AFQjCNER0dJSVMqwQi6u9rDLwKp-nAKBhw&bvm=bv.49784469,d.ZWU&cad=rja

"More importantly, despite all the benefits of higher pixel resolution, the shrinking of pixel pitch is fundamentally not preferred in terms of the photo-response. Smaller pixel size leads to a reduced photo-sensing area, which ultimately limits the pixel full-well capacity. As will be explained in the next chapter, decreasing pixel full-well capacity damages the image quality by reducing the maximum pixel signal-to-noise ratio and the dynamic range."

Of course it doesn't make sense talking about different pixel sizes in different technologies since there would be a huge amount of others factors to be taken into consideration.

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