Archived posting to the Leica Users Group, 2001/03/26
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Stephen Patriquen wrote: > The CCDs used in most digital cameras used to be made > in 120mm wafers (they may be up to the new 300mm size > by now). > > I once had a discussion about them (this is ten years > ago, when the first Kodak/Nikon pro digital cameras > were just out) at Kodak's TEC "country club" research > facility outside Rochester. > > Almost all the production CCDs have defective "dead" > pixels, and - sort of like cutting a diamond - Kodak > would cut up the wafer to produce the most efficient > mix of usable chips. > > However, it turns out that even back then, some of > these wafers were perfect. That is, they produced a > 120mm CCD - equivalent to a piece of 120mm round > digital film. (So, theoretically, you could make a > full-frame 120 digital back.) > > These chips, unfortunately, are worth about the same > as diamonds. It was intimated that these "perfect" > wafers were reserved for the US military, and no doubt > ended up in a geosynchronous orbit over interesting > parts of the world. <snip> or maybe in instruments like this: http://www.cfht.hawaii.edu/Instruments/Imaging/CFH12K/ strictly available light ;-) Dennis