I've just had a quick look at Vic Menard's book on collimation. Your telescope is, I think, F4.8. If you are not using a coma corrector you have a fair bit of latitude on the secondary alignment, your tolerance for that is actually around 7.5mm, but if you are going to adjust it you should get it as close to the centre of the centre spot as you can. Not such good news on the primary collimation at F4.8 I'm afraid - you should be looking to get that to within 0.5 of a mm or so. Much easier with a Cheshire. If you are doing it when it is getting dark shining a torch in the hole on the side of the Cheshire can be helpful in making things stand out more. As Glen said don't worry about the offset at all - it may already be built in to the way your secondary has been attached anyway - it is on my 130mm F5 Skywatcher, if not then your primary adjustment will just tilt the primary a little bit, which you will not even notice.
Last edited by rrussell1962; 18-04-2020 at 04:34 PM.
|