Originally posted by k10dbook Because they obviously cannot make one chip the size of a medium format in one piece that the camera can use, otherwise they would have done it. I'm not a computer scientist, but tell me why there aren't a one chip the size of a medium format camera lens circle?
Thank you for your kindness!
Actually it has more to do with the cost, waste and economics of the process. Can they do it? I'm sure they can. Is it economically feasible? Probably not. The silicon wafers are cut from long, grown crystals called boules. These are then sliced, masked, and the devices are printed onto them (this is waay simplified). If a 6-inch diameter wafer yields, say, 160 15x24mm devices (actually less), and if we assume a defect/rejection rate of 20 percent, we have a yield per wafer of approx. 128.
Now, let's make 48x36mm devices on that same 6-in. wafer. Now we can only fit 32 devices (actually less) on it. Minus that same 20 perfect rejection, and we have yield of around 25. You throw away a lot more money with each reject, now. It costs roughly the same to have created each wafer, so the larger devices will have to sell for
at least five times what the APS-C size devices sells for. Couple with with the fact that you are essentially making the smaller devices at a five-times faster rate, and there is very likely not a large enough market at this time, at that price, for devices that large.
It's all a trade-off. If the outcome was guaranteed, everyone would be doing it.