I'm new to astronomy, but i kid you not, i was viewing the moon this morning (Mon, 22/04/19 around 5am BST, Liverpool, UK) at 500x mag with my 130mm/900mm Newtonian and although there was a bit of image wobble, i could see really well! I'm expecting almost everyone to laugh at me or call me a liar but i swear it's true! I put a 3.6mm plossl on the 2x Barlow, effectively making the plossl a 1.8mm, just to see how bad the image would be, but was shocked when i actually managed to get a sharp focus ?? It's opened my eyes, literally, to what's possible when seeing, optics and collimation etc all come together perfectly! I'm assuming it would never happen with anything else as the Moon is very unique in that it's relatively huge, very very bright, and obvs silly close to earth, in astronomical terms.