A picture of the moon that I took on my 8” Celestron sct has a large bright spot in the image. I used
a 90 degree diagonal, 2x Barlow, and a 25mm eyepiece in the camera adapter. Where does such a large hot spot come from? Bad collimation or something else? I tried to upload a picture I took using my iPhone but the image was too large. 500kb limit is too small.