Peter Drew

We have several hundred books including all the usual favourites, sadly it's rare these days that anyone takes one from the shelves. ☹️

Bear in mind that it is you that will have to manage 95% of the experience on her behalf so it's largely what you can operate. Welcome to SGL. 🙂

You can collimate using Jupiter. If you slightly defocus you will see a ghost annulus of Jupiter and depending how concentric that annulus is will be a measure of your collimation quality. It has the advantage of not twinkling like a sar does so helpful during poor seeing. In good seeing a star is more accurate. 🙂

"No World class images this time" ? Which world? 🙂

Probably not worn but there might be some sort of inclusion into one of the bearings to cause the roughness, these mounts have a history of bits of swarf etc in the system. 🙂

I would try it before doing anything radical and if it gives good images I would leave well alone for the time being. 🙂

So sad in so many directions. I had the pleasure of meeting David and being at one time a professional telescope maker myself I am well aware of how much effort goes into a bespoke telescope. A major loss to this craft. My condolences to his family and friends.

Worth a try but I'm not sure if it would work. In general, achromats are corrected in green so blue and red are usually worse. I don't know whether it's possible to correct the latter two by using software before adding them together again. Hope it is! 🙂

Could be a minor internal temperature plume effect. 🙂

It could be worth loosening the 6 screws that hold the corrector retaining ring and then retightening them with just light finger pressure. The mild astigmatism that you describe has often been reported due to the over tightening of these screws. 🙂

I would think the difference would mainly be the degree of image attenuation. I'm visual only but the IR/UV KG3 might be suitable for imaging only. The standard blue filter is usually available from Lunt or one of their vendors. 🫠

The caps are glued on and are quite brittle, trying to prise them off with a knife or screwdriver can easily chip them. I had success by gently heating them with a hair dryer. 🙂

I would join you Olly but I'm not even an astrophotographer. 🙂

Schmidt-Cassegrain mirrors are single point central mounted with no apparent distortion problems. My very thin 30" mirror of conventional profile is centrally mounted via a 3" core. It rests on a 30" disc of heavy duty bubble pack having 1/2" cylindrical bubbles that cannot be "popped" by hand providing in the order of 750 suspension points. The backplate stub that located the mirror was undersize and a peripheral strap was adjusted to lift the mirror clear of the stub. Initial astigmatism was cured by wrapping insulation tape round the stub to make a good fit on the core diameter and dispensing with the strap. I made a few 10" Newtonians with conical profiles ground on, cored and centrally mounted like a SCT with no issues. Or retaining clips. 🙂

Binoculars are a precision instrument at a reasonable price point so I think it unlikely that there would be that level of inaccuracy. Most binocular vendors would accept a return if a model supplied did not reach the IPD specified by the purchaser. Difficult to advise do's and don'ts as binoculars are such a personal thing, common pointers are weight, magnification limit for hand holding and, as in your case, IPD range. Porro prism binoculars tend to be better value price for price than roof models. The only real test is to try and see for yourself. 🙂

That looks a fairly significant dent and from the position might have displaced the setting of the secondary holder and consequently the collimation. Check that none of the spider vanes have been bent out of shape. All can eventually be sorted out and the telescope should perform well. 🙂

Use it to check your collimation and then send it back. 🙂

I've used three large Grubb refractors, the UCL 15", the Stonyhurst 15" and the 8" at UMIST. I have to say I was a little disappointed with the performance though their condition at the time might have been partly responsible. I offered to clean the UCL 15" but "red tape" got in the way, I had permission to clean the Stonyhurst 15" but considering most of the problem was between the lenses and the condition of the cell was such that I was reluctant to dismantle it. We repaired a few components and at least got the telescope operating again. I did remove the cell from the UMIST 8", dismantled the objective and cleaned and reset the components. Little improvement but the location in central Manchester doesn't help, my 8.5" refractor refigured by Es Reid is better. The 8" Cooke refractors at UCL (London) and Moor Park Preston are superb. 🙂

A refurb looks overdue! 🙂

It's most important that your IPD matches the exit pupils of the binocular or you will get, what you have found, dark patches in the field of view. An IPD of 76mm is unusual but I would have thought that a suitable binocular exists. If the exit pupils of the binocular are greater than your eye's pupils then there can be a bit of compromise, unfortunately larger and higher magnification models tend to have small exit pupils. There are mechanical stops on the hinge of a binocular that determine the degree to which the IPD can be extended, maybe this can be modified, as a tinkerer this wouldn't stop me if all else failed! 🙂

There will only be radio astronomy and meteorology to choose between. ☹️

Every amateur will have a 6" aperture SeeStar. 🙂

Pretty much ideal. I work on a similar principle with fixed housings for large Dobsonians that are deployed from them via wheels on rails. A 30" is quicker to set up from scratch than a 3" refractor on a GEM. 🙂

I think most amateurs would be satisfied with most of the in focus star images shown on that graphic despite the aberrations that caused them. Good luck with getting seeing conditions good enough to see them like that, specially in apertures above 6". 🙂

Always a good way to break into a market if you can afford it. Provided the product is good, and the Askar seems to be considered good, an entry price that is tempting is offered. Eventually "bargains" become "good value for money" when prices are increased. 🙂