450C questions

[vorkus]

I'm eyeing up the 450c but the specs are confusing me a bit.  It looks like it would be good for pulling detail out of smaller targets, which is what I had in mind.  The specs I see says the chip is 10mp but the camera stats say 5mp.  I know a manufacturer will waste some pixels for a specific application, but there seems to be more going on here than that.  Also the well depth looks very shallow: 7950.  That seems a bit tight especially when you factor in light pollution, or am I missing something?  It certainly wouldn't need a 16bit ADC; more like 14, right?  I also saw an earlier thread that didn't seem to like the QE. It didn't look that bad to me.  Anyone who could put some of this in perspective, I'd be appreciative.

John

[vorkus]

I found one answer on my own.  The 10mp versus 5mp is because it is an interline chip.  Every other pixel is hidden behind an opaque mask.  To eliminate the need for a shutter, it copies the contents from the visible pixels to the hidden ones.  Then the image can be read at leisure while the chip is collecting more photons.  The design is very fast since it is a bit shift operation within the chip.  The down side is that it reduces the QE which is somewhat mitigated by the use of microlenses over the visible pixels.