The next EOS R system camera gets a mention again [CR1]

Ladislav

EOS RP
Feb 13, 2013
317
34
37
Czech Republic
If you are comparing pixel to pixel you're totally missing the point when one has pixels that are one-half the linear dimensions and one-fourth the area of the other.

Viewing a 22-23 MP image at 100% on a 23" HD monitor is like looking at a piece of a 60"x40" enlargement.

Viewing an 88-90MP image at 100% on the same monitor is like looking at a piece of a 120"x80" enlargement.

Viewing the 88-90M image at 50% gives the same enlargement size as viewing the 22-23MP image at 100%. Both are the same sized piece of a 60"x40" enlargement.

Since noise is random (that's what makes it "noise"), averaging multiple noisy pixels together makes the averaged larger pixel less noisy and reduces the standard deviation between each pixel than the four smaller pixels it replaced.
I disagree. You are considering only theoretical properties, not construction limitations.

Possibility of noise is defined by Signal-To-Noise ratio (SNR). SNR affects readout of the pixel. Larger pixels generally have better SNR than smaller ones. That's why FF camera with can achieve higher ISO with less noise than ASPC camera with similar number of pixels.

But let's for now consider that both large and small pixel have same SNR. When you read large pixel, you get read noise X. When you read small pixel, you get read noise X as well (because we are considering same SNR). To create large pixel from small ones, you need to read 4 of them because combining happens on digital representation, not analog => input read noise is 4 times X. Now your digital processor has to work to average that 4X. Since it has in theory 4 times more information, it can produce better result than readout from large pixel.

But that is just theory because large and small pixel does not have same SNR - that is the whole point why we don't have only high megapixel cameras with ability to bin pixels. Using smaller pixels reduces sensitivity and dynamic range. There is also fill factor - not whole area of pixel is photo sensitive. Fill factor means how big area of the pixel really captures the light. Fill factor is dependent on manufacturing technology but again, larger pixel has larger fill factor than smaller one because amount of electronics does not increase with pixel size. There are other technologies like microlenses or back illuminated sensors which improve fill factor significantly but they are much easier to do right on larger pixels.
 

Michael Clark

Now we see through a glass, darkly...
Apr 5, 2016
447
154
I disagree. You are considering only theoretical properties, not construction limitations.

Possibility of noise is defined by Signal-To-Noise ratio (SNR). SNR affects readout of the pixel. Larger pixels generally have better SNR than smaller ones. That's why FF camera with can achieve higher ISO with less noise than ASPC camera with similar number of pixels.

But let's for now consider that both large and small pixel have same SNR. When you read large pixel, you get read noise X. When you read small pixel, you get read noise X as well (because we are considering same SNR). To create large pixel from small ones, you need to read 4 of them because combining happens on digital representation, not analog => input read noise is 4 times X. Now your digital processor has to work to average that 4X. Since it has in theory 4 times more information, it can produce better result than readout from large pixel.

But that is just theory because large and small pixel does not have same SNR - that is the whole point why we don't have only high megapixel cameras with ability to bin pixels. Using smaller pixels reduces sensitivity and dynamic range. There is also fill factor - not whole area of pixel is photo sensitive. Fill factor means how big area of the pixel really captures the light. Fill factor is dependent on manufacturing technology but again, larger pixel has larger fill factor than smaller one because amount of electronics does not increase with pixel size. There are other technologies like microlenses or back illuminated sensors which improve fill factor significantly but they are much easier to do right on larger pixels.
But if both sensors are the same size, there are also more of the smaller pixels than the larger ones. When downsizing the image from the sensor with the higher number of smaller pixels to match the number of pixels of the image from the sensor with lower number of larger pixels, the averaging of the larger sampling reduces the total amount of noise without reducing the total signal, so the SNR goes up.
 
Dec 24, 2017
8
1
Alpine, Ut
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This could potentially be the camera that brings over to FF mirrorless / RF mount. While I don't need 70MP, a higher end body than the EOS R is what I'm looking for. IBIS, faster frame rate, better ergonomics, potentially some improvements in AF, dual card slots - these are all features I would welcome.

I will keep looking forward to Canon's camera body and lens offerings in this mount. In the meantime, my DSLRs and EF/EF-S lenses, including some L glass serve me very well.
Everyone needs 70 megapixels - they just don't know it until they've tried it! :cool:
 
Reactions: pj1974