I took a few pictures during the total solar eclipse of 2019. I noticed in my images that the "width" of the Moon is greater than the "height". I know that the Moon is oblate by about 0.0012 (wikipedia). However, I am noticing a greater effect (0.040).
The width of the dark disk of the Moon during totality is approximately 2454 pixels (though there is some blurring so the exact dimension is hard to tell).
The height of the dark disk is approximately 2434 pixels.
This results in a flatness of 0.04 (which is about 38 times greater than the value posted in wikipedia).
Any ideas why?
NOTE: The image of the Sun (with solar filter, no eclipse) appears to be circular. So, I don't think it is lens distortion.
Canon T6s, 1/50 shutter, 100iso, 1000mm Schmidt-Casegrain telescope with T-mount, no solar filter.