Peter Drew

Obviously can be done, not ideal but maybe noother option. I seem to remember something about the Gunther Roth telescope. It might have been an external fixed objective fed by a siderostat, the view being transferred indoors.

The short answer is no, 1.25" and 31mm are virtually the same. . Did you mean 50mm?

Close, but no cigar! Right subject though.

Sol finder for a 60mm LuntPT?

I get to use a number of these and similar each year, they are the main ones that visitors have problems in setting them up or using them. The majority have quite good optics but the rest of the design leaves a lot to be desired. As mentioned, the finder system is poor and the balance is upset by the weight of the telescope being over the pivot point. It's a pity that the likes of Celestron and others who have good reputations within the higher price areas offer such telescopes that seem to have the accent on form over function. Entry level is the point at which a beginner is either put off or hooked on astronomy.

May I be the first to help you spend your money? . Tough one to call on paper, if the TS one is as good as they claim then I would go for that one to best suit your purposes/ The extra that the TS costs could soon be swallowed up by replacing the focuser on the Evostar if it proved necessary.

Nice one Olly. Your report, coming from a confirmed "sceptic" nicely endorses this particular telescope, Alan would have been delighted. The optics of recent SCT's seem to be well sorted in manufacture and reliable in performance, however the good performance is fragile, it doesn't take much in the way of collimation error or unsuitable seeing conditions to let them down. Fortunately, collimation is easy and good seeing is just a matter of patience.

You know what I would do Olly , there's one already over the setting circle.

When siliconeing a secondary I place 3 coins between the secondary and the holder face to make sure the secondary is fixed without tilt. The coins are removed once the silicone has set.

The prime forum for anything solar.

I would post a piture of the defect on Solarchat, plenty of expert advice about such problems on there.

Congratulations to you both.

Perhaps 3 collimaton screws would produce 6 diffraction spikes in the same way as a 3 vane spider does?

Residual spherical abberation often found in short focus lower end achromats can also exhibit a spikey edge to star images.

Refreshing to have an "honesty" themed thread, here's my contribution. I'm fortunate to have been observing longer than most with access to a wider range of apertures and designs of telescopes than most. My opinions are based on this and very much influenced by my current age. I wouldn't now purchase a small refractor of any type, I like their crisp textbook star images but I'm not into double stars or imaging. Struggling to see much DSO detail doesn't satisfy me, taking one to a dark site improves things immensely but I'd sooner take a 8" Dob for that. My 102mm Vixen flourite and 127mm F15 triplet are probably my least used telescopes. I have very large binoscopes for wide field views with good light grasp and have an incoming 80ED to pair with another to form a rich field binoscope. These days my eyesight is such that I seem to need a much larger aperture to see planetary detail as well as the younger keen eyed observers do, if the seeing conditions don't suit a large telescope I find something else to do. Happily, to provide a balance, nothing beats a refractor for solar observation.

Excessive sherical aberration IMO.

Me too! Doesn't a smaller chip effectively increase the magnification and exposure time which would tend to negate the hoped for advantage. Installing a secondary support system to replace a corrector would be an interesting challenge, possibly using a circle of selected window glass would be adequate for a trial.

Fair enough. My feeling though is that it will all boil down to acceptance level. The results might satisfy those who are happy with phones held up to an eyepiece but I can't see a following from the gurus on this part of the forum.

It's against my normal nature but I'm rather pessimistic about this one. The SA from an uncorrected F2 sphere is going to be more than "some", the advertising significantly underplays this issue IMO. I look forward to seeing some images in due course and hope I'm wrong.

An 8mm eyepiece is going to give too high a power for most sky conditions, a 12mm one would see more use.

Best Newton's rings so far!

I occasionally use my 8.5" refractor for white light and Ha observation. I have to say that you need good conditions to benefit from the aperture. You can always stop an aperture down though.

Good plan butI fear that with the planets being so poorly placed at the moment, any decent telescope is going to struggle to give images to match those that you recall with your previous experience thereby giving a wrong impression.

I used a similar arrangement to support a 6" minor axis secondary mirror on my 30" build. Seems to work OK so I'm sure yours will.

I think the only way to sensibly increase the contrast is to double stack it. If you think the cost is sensible that is!