On Jun 3, 2021, at 15:53, John Jennings <johnrogerjennings@...> wrote:



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It's a different world with CMOS sensors. I've been shooting CCD's for 20 years and CMOS for about 1 1/2 years. Fast computers mounted on the telescope, SSD drives, lots of disk space etc. Learning the ins and outs of CMOS gain curves and modes. It's a new world. And they have their issues including flat frame calibrations. But they are here to stay and the performance can be incredibly awesome in certain configurations for certain purposes.  In dark skies with good mounts and tracking, all this is less important.

The read noise being so low and the cameras so fast, makes them ideal for short exposure narrow band imaging in the city. I'm getting some pretty good pictures with CMOS color cameras too with broadband and pseudo narrowband OSC color filters. I have done quite a few calculations and tests of my CCD vs. CMOS cameras. In one calculation/test, a CCD sensor with 9e (typical 9-10) read noise vs. the CMOS 1.5e read noise in my magnitude 18.1 suburban skies (with a broadband light pollution filter) results in a optimal CMOS sensor exposure of 22 seconds vs. 700 seconds for the CCD before the background rears its ugly head. (same level of photons gathered)  Everything was normalized including the pixel size and scope. Really just different read noise parameters.

The 5.94u pixels on my new QHY400C OSC seem to be a pretty good match for my AP155EDF too. And I just like the simpler work flow.  And the raw file size for this full frame larger pixel sensor is a reasonable 48 MB before debayering. I don't think Sony has released a mono version of this sensor. That would be great. The IMX410 is the sensor used in the Nikon Z6.