Which image scale figure to use?

I calculated that with my equipment the image scale is 1.14. Plate solvers keep reporting it to be 2.18. Should I change my settings for 2.18?

I used this formula to find my image scale:

pixel size (microns) x 206.3 /focal length in mm = image scale in arcsec/pixel

thanks

Try this pixel scale calculator https://astronomy.tools/calculators/ccd.
Note that if you are binning your image for plate solving then the pixel
scale will be 2x higher (binning 2x2). In other words if your 1x1 pixel
scale is 1.14 as calculated by the linked calculator, but you are binning
2x2 then the plate solver will show 2.28 (2x1.14). Also note that your
actual solved image scale will likely be slightly smaller or larger than
the calculator shows.

I suspect you may be binning your images and that’s why it shows 2.18, and
the actual solved image scale is just slightly lower than the theoretical
binned pixel scale.

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