Quote:
Originally Posted by gregbradley
No, its gets the same, just how that is divided up by the number of pixels. It gets a broader area but that's not per pixel but per area of sensor. What counts is what Suavi mentioned, light per pixel which would be more for a larger pixel and larger for a CCD as it does not have 40% of the sensor surface taken up with surrounding CMOS circuitry per pixel. So standard CMOS sensors unless they are BSI (backside illuminated) lose 40% of surface area to surrounding per pixel circuitry.
Later Sony BSI sensors like in the Sony A7r2 are designed to get that 40% back by flipping the sensor over and leaving the circuitry on the other side of the sensor. It started with the Sony RX100 ii or iii.
Greg.
Greg.
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Nope, pretty sure it will get 6x the number of photons in each pixel because the bigger pixels intercept 6x as many photons. Nothing to do with surrounding circuitry - that determines the QE and the 1600 and 16803 seem to be about on par there.
the maths is not an end in itself, just a systematic way to work through the myriad of interacting parameters without spending a million bucks on hardware.
This is not a Sony sensor, but with a QE of around 0.6 (guess) and read noise that can be <1e, it is surprisingly close to "Nirvana" of QE=1 and RN=0. There is not much more opportunity for anyone to develop sensors much beyond where they are, when they are already so close to perfection. BSI can give much better QE with the small pixels on mobile phones, but isn't anywhere near as significant with 3.8 micron pixels. Maybe there will be a bit more QE from BSI and more dynamic range is possible, but the days of new astro sensors being waaay better than their predecessors are over. Maybe the way of the future will be much larger sensors, either with lots more pixels or with bigger pixels, but the Panasonic chip in the 1600 is the only largish CMOS mono chip out there for now. There are a few very interesting CMOS chips in the medium format world (where the 16803 came from), but they are not mono and are 5 figure $.
edit: for interest, the following comes from an Aptina white paper(no longer available) that suggests that BSI and FSI technologies are about equal at 1.4micron pixel size - it doesn't mean that BSI will not be used with larger pixels, just that it will not be quite as significant in that regime. In particular, it is pointed out that BSI pixels have worse crosstalk (lateral blooming) presumably because there is no backside electrode structure to stop it:
"For 1.4 micron BSI pixels, QE is typically in the 50-60 percent range with crosstalk in the 15-20 percent range. The combination of BSI’s high QE and somewhat degraded crosstalk at 1.4 micron results in a net overall image quality that is comparable to FSI for 1.4 micron pixels.
Today, 1.1 micron BSI pixels are still in the early stages of development, but when they are production-ready, they would be expected to have a QE approaching 50-60 percent with crosstalk in the 10-30 percent range. These 1.1 micron BSI pixels should be outperforming 1.1 micron FSI pixels at that point due to the fabrication challenges in shrinking FSI pixels to 1.1 micron.
A tipping point for BSI will be the 1.1 micron pixel node where FSI will likely be unable to achieve the market-required performance – necessitating a transition to BSI for applications that require this smaller pixel."