Staraddict

Many spotting scope objectives (unless you have very expensive ones) are not that well corrected for extreme magnifications, opting for portability (hence the fast F-ratio) and wide, flat field of view. If you have a barlow handy or can borrow one on a star party, give it a shot.

I bought a cheap 3x Barlow lens for my Skywatcher Heritage 5" - mostly to give it a shot (the 2x Barlow I bought is much more expensive and of better quality). I can't see anything at all if I point at the stars, but I expected this... I tried Jupiter and I saw a strange image! I don't know what it was.... First I had to collapse the tube because the magnification was huge.... And once collapsed that's what I saw (below). I don't know what it is.    It can't be a poor image of Jupiter because it doesn't look like Jupiter and besides the magnification was huge, much higher than it would have been for Jupiter with the eyepiece I was using, that's why I had to collapse the tube. I was using a 25mm eyepiece, so through the 3x Barlow lens it should have been like a 8mm eyepiece (approximately). With a 2x Barlow Jupiter was still relatively small, but I could see it clearly, and with the tube fully extended.

Sorry for the horrible quality. I just kept it out of curiousity, so it has not been edited or anything. Is it maybe just some sort of reflection of the light emanated by Jupiter on the mirror? This only happened while pointing at Jupiter. I also tried on another day and it was the same (but I didn't take any photo). I am just curious for an explanation, thanks!