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Generally speaking modern DSLRs have very small pixels compared to most Kodak chip based mono CCDs.
Small pixels generally speaking usually means more noise, less dynamic range and smaller well depth (meaning bright objects fill the pixel too easily and you get bloat and overexposure).
You see this sometimes in DSLR images where the stars are all white because they are all overexposed due to small wells of the small pixels.
Some DSLRs have large wells and pixels. You have to do your research but a 24mp APSc sized sensor is going to have small pixels probably half or less than half the size of a typical CCD (9 microns).
Mono of course as said already makes every pixel count so no 4 pixels to make 1 image pixel. Bayer CFA rob light transmission. This is obviously a big point as Sony recently improved a CFA on one of their cameras and claimed a 20% increase in light transmission from a new set of colour dyes for their CFA. Mind you there would be light loss from RGB filters as well. Perhaps not as much as they are higher quality filters.
DSLRs are usually CMOS sensors. Rarely CCDs are used, older Nikon D50 and D70 are probably a rare camera that used one. CMOS means the circuitry like analogue to digital converter and amplifiers are etched in the area around each pixel ie each pixel has its own circuitry. This typically takes up 40% of the surface area of a sensor so only 60% takes light, some of that is lost through the CFA, there is blur applied by the AA filter and no doubt light loss there as well (it also blocks the Ha and IR response).
So smaller pixels, 40% loss due to circuitry etched in around every pixel as opposed to circuitry being completely separate on a CCD so 100% surface area used for collecting light, CFA light transmission losses, then 4 pixels to create 1 image pixel is a substantial light loss, plus the AA filter creating a blur and more light loss on top of small wells, low QE (often below 25% compared to around 50% for most CCDs).
Add to that most CCDs are 16bit and most DSLRs are 12 bit or later models are 14bit which also translates to lower dynamic range. Read noise may be higher in some cases as well.
So a lot going against them. DSLRs vary a lot in QE and well depth though so some research would be good. The new Sony A7s may be the ultimate "DSLR" (its a mirrorless) with large pixels and super high ISO performance (not to mention 4K video).
Greg.
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