Plate Solution with CHI-1 CMOS (QHY600M) Image Train

Reggie Jones

Hi Adam; trying to understand why I received a plate solution using these particular parameters and not the parameter I expected.  The new Telescope Live QHY 600M camera on the CHI-1 equipment images at 2x2 binning.  The image scale for this image train is 0.196 acrsec / pixel at 1x1 binning.  I expected that when using the Image Solver script to get a plate solution at 2x2 binning, I would need to use a resolution of 0.784 arcsec / pixel.  When I did, Image Solver would fail to get a solution.  However, for grins I tried a resolution of half that at 0.392 aresec / pixel and it solved after 4 iterations but I'm not sure why this resolution worked and the resolution at 0.784 failed.

Hoping you can educate me on how to correctly think about this...

Thanks

Reggie

Reggie Jones

Ok, I think I figured this out; I was thinking in terms of total area of the 2x2 pixel (7.52 microns x2) and not just (3.76 microns x 2) and overthinking this and confusing myself.  Please let me know if I have this right.

R

BlockHead

Yeah.. you just multiply 0.196 x2 (basically 0.4).

You either keep the focal length the same and adjust the plate scale (by the ratio of the pixel dimensions from 1x1 to 2x2) or you keep the pixel size the same and adjust the focal length to yield the same plate scale.

The former makes the most sense to me. You literally are changing the size of the pixels... so if you make the pixels larger (binning) then you need to increase the number "/pixel by the factor of that increase.

-the Blockhead

Reggie Jones

Thanks Adam!