So you are saying a 22 bit ADC is overkill. Wonder if Pentax knows that? BTW, Rob's explanation was clearer, but still not documented for my curiosity.
-- graywolf http://www.graywolfphoto.com http://webpages.charter.net/graywolf "Idiot Proof" <==> "Expert Proof" ----------------------------------- John Francis wrote: > On Sat, Sep 16, 2006 at 05:45:09PM -0400, graywolf wrote: >> Can you provide a reference on that? A quick goggle search* finds >> nothing the contradicts my explanation. Your comment may be accurate on >> the quantum level but I do not think we can quite apply it to current >> image sensors, but would be interested in seeing something about where >> you are getting that from. Photons, like all quantum particles, are very >> slippery critters and probably act that way, but I do not know of any >> photo diode that gives out a quantized signal --in a macro world sense. > > The point is that you're not in a macro world. The change in voltage level > that would be indicated by the smallest possible change in a 22-bit number > is well below the change in voltage that would be caused by the presence of > just one additional electron in the sensor site (by a couple of orders of > magnitude). You're trying to measure an "analog" quantity to a precision > that puts you firmly in the quantum domain. > > -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
