Got this last year thinking I would do some solar imaging but not really got around to it. Optics are great. I replaced the weak point of these scopes, the ITF filter, with one from Beloptik in Europe. Sun photo taken with iPhone The filter apertures on the diagonal look like 15mm at the tube end and 10mm below the eyepiece. The screw which tightens the diagonal is broken but the diagonal is a tight fit so it’s not a problem.