Reply To: Pixel Value and Exposure

Forums Imaging Pixel Value and Exposure Reply To: Pixel Value and Exposure


Dear Fellow Astrophiles
thank you for providing me with information and links, which are valuable supports for better direction of my studies. I immediately read all the parts that are most relevant to my problems. However, the fundamental problem is not addressed: what is the general characteristic PixelValue- Exposure? The magnificent articles report precisely such graphs, but only for narrow shutter speed ranges. In that case, the general curve certainly can be confused with a straight line. Therefore, a PV-time proportionality relationship can be considered valid, and thus it is easy to reduce any photometric reading to a single shutter speed. However, when the shutter speeds are very different from each other (e.g. varying from 1/200s to 4 s), a curve emerges, virtually similar to the one in the figure. Reducing the PV readings on each frame, e.g. on those taken during a lunar eclipse, becomes difficult. Apparently no AA considers this problem.
If anyone has addressed this before I would be happy to exchange some thoughts with them.
Again, many thanks to you all.

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