Quote:
Originally Posted by Stefan Buda
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Another issue with these sensors, that I don't really understand, it that they seem to have more pixels than what is actually being used - at least some of the sensors that I have looked at. If that is the case then maybe the physical center of the chip is not the same as the optical center?
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Yes interesting point, I've often wondered the same thing, but maybe within your comment we part of an answer. Perhaps during manufacturing those unused pixels are used for some form of
individual camera calibration to move the sensor's geometric center in X-Y (electronically/via firmware/software) in order for the sensor center to be coincident with the optical center or at least for it to be at the geometric center of the camera's flange mount. That way when manufacturing lenses they could do similar by aligning the optical and flange center and thereby produce, in the end, a system which was as optically aligned as best as possible, manufacturing tolerances notwithstanding, with whatever lens is fitted.
Of course that's in high volume camera manufacturing, manufacturer's may do otherwise in different sectors of the market.
BTW ... just
spit ballin' here
Best
JA
*Another possibility: Of course it's also possible/necessary for camera sensors with a pixel shift or electronic vibration control function to have some "spare" pixels to use for such functions in order to "maintain" the sensor size whilst actually "moving" the sensor, by using different pixels. Such usage (electronic vibration control) may not be used in astrocameras, but astrocam manufacturers will often source their sensors from suppliers to the higher volume photographic camera market in which they are used...... BTW and food for thought: I think I would be a great idea to try to use such as a form of pixelshift in a real time-ish system to provide
some form of adapative optical control, be it only in X-Y, (certainly nothing like a flexible optic.).