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. I admit my physics knowledge is not as up to date as it could be. But I do believe folks are trying to digitalize non-digital phenomena, if the information was digital we would not need an ADC.
*Unfortunately, the liberal arts university here in Boone does not have much in the way of science texts in its library (singular). Sigh, I do miss having the U of M libraries at my fingertips, so to speak. -- graywolf http://www.graywolfphoto.com http://webpages.charter.net/graywolf "Idiot Proof" <==> "Expert Proof" ----------------------------------- John Francis wrote: > On Sat, Sep 16, 2006 at 02:47:56PM -0400, graywolf wrote: >> Still trying to turn things around. The sensor is simply a photocell. >> The brighter the light hitting it the higher the voltage output. >> Visualize analog as curves, digital as steps. Don't get them crossed in >> your mind if you want to understand what is going on. > > Unfortunately, Tom, you're incorrect here. The "analog" output > from that sensor is still quantized into discrete steps (either > the number of electrons in the well, or the number of photons > that hit the sensor - take your pick). Both of those numbers > are below 2^17 (around 128000). So you're never going to get > more than that many different values in your digital output. > (Or in your "analog" input curve, either, if you look closely). > > > -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
