ngwillym

you might fid something here:- International Dark Sky Association | International Dark-Sky Association

All, thanks for the advice.. Secondary was removed and re-seated on its pivot and the collimation screws levelled up. A quick daytime collimation, followed by a star collimation has it looking much better - not perfect, the seeing wasn't really up to it - but I now have a doughnut to work on. There's a forecast for mist/fog over next couple of days, so hopefully the seeing will be much steadier Happy days Neil

Thanks Peter - I wasn't sure if it was just collimation error or something preventing the main mirror racking in and out. I did a daylight collimation using thus approach - Daylight Collimation (robincasady.com) and it looked pretty good - hence me suspecting something more that just a dodgy secondary. As it the Hyperstar version, its not too difficult to remove the secondary for a check-out. Neil

Thanks @dweller - I'd thought of that too - used a flashlight to check all around the perimeter of the main mirror- but can't see anything untoward. Ahhhhh, but something else does just occur to me - it might be a protruding fixing screw from the electric focuser - I'll check tomorrow

It spent most of last year stored in a large plastic case in my dome (which has a frost protection heater and dehumdifier) as the planets were too low at my site to do any meaningful observing. I decided to re-mount it and do some lunar work. BUT on trying to check the collimation - things didn't look right. I've attached 3 pics - one from inside focus, one at best focus and one outside focus. (images taken on 18th Feb - seeing wasn't brilliant but even so I would have hoped for a much better star profile that what I got) anyone have any ideas what's causing this - any a

Agree with Aramcheck - out of focus and well out of collimation. What target were you aiming at? If its any sort of nebula it's unlikely you'll see much if anything at all in a live view - especially if the focus is only just slightly off. And the odd stars you're seeing might just be hot pixels. First sort out the ocllimation, then the focus. Neil

Nice one. That takes me back to when I did the same thing with a Philips Toucam - quite a few years ago now

From Setup - > ~Display -> finder Rectangle and then just double click on the 0.00 under 'rotation' for your chosen rectangle and experiment with numbers between 0 and 180 until it looks the same as your FOV

Drift alignment:- Accurate Polar Alignment with Your Telescope - Sky & Telescope - Sky & Telescope (skyandtelescope.org)

I hope you've got a good stock of the cloud gun

According to the NINA manual " If an OSC camera is used, the raw bayered data is saved" - I'm guessing you'll need to debayer the saved image?

do you need an actual box or splitter cable - plenty of those on ebay - 4, 6 or 8 way. Neil

Or there's this guy Telescope Repair - SC Telescopes.com service repair. Did a great job on reviving my15 year old Celestron C11

And to answer F - that screw is to stop the scope/dovetail slipping all the way out of the saddle and ending up on the floor

Yeay. A reason to open the dome - as NEOWISE was below my tree line, so its not been used for days/weeks