The M43/MFT Shaft !

If your chip or sensor has defects no amount of cleaning will make it operate - I don't understand what this has to do with dirt or Nikon - or the graduate for that matter (I've only read the Charles Webb book, never got around to watching the film)

http://www.cambridgeincolour.com/tutorials/digital-camera-sensor-size.htm (cost of production 2/3 down)

"When full-frame sensors were first introduced, production costs could exceed twenty times the cost of an APS-C sensor. Only about thirty full-frame sensors can be produced on an 8 inches (20 cm) silicon wafer that would fit 112 APS-C sensors, and there is a significant reduction in yield due to the large area for contaminants per component. Additionally, the full frame sensor originally required three separate exposures during the photolithography stage, which requires separate masks and quality control steps. The APS-H size was selected since it was then the largest that could be imaged with a single mask to help control production costs and manage yields.[19] Newer photolithography equipment now allows single-pass exposures for full-frame sensors, although other size-related production constraints remain much the same."

from http://en.wikipedia.org/wiki/Image_sensor_format

and

"yield is comparatively low because the sensor's large area makes it very vulnerable to contaminants—20 evenly distributed defects could theoretically ruin an entire wafer. Additionally, the full-frame sensor requires three separate exposures during the photolithography stage, tripling the number of masks and exposure processes.[7]"

from http://en.wikipedia.org/wiki/Full-frame_digital_SLR

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James
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