Peter Drew

More pics. The OTA's are modified SW Startravels. Each one has a 3" minor axis diagonal to start the 90 degree angle followed by pairs of diagonal prisms for IPD adjustment. Each OTA is sprung loaded with adjusters to quickly perfect the collimation. The mount is a simplified version of the TTS Panther mount. Not had chance to try them on the night sky yet.

My latest 150mm F5 binocular telescope.

The correct focus position was set up using an optimally tuned PST less its 40mm objective. The subsequent mod is a stage2 so the black box is empty. The digonal containing the blocking filter fits in an aperture machined in the rear face of the black box. Spacers have been supplied that make up any difference in the post etalon focus. Any very small adjustments for different eyepieces are by way of the OTA fucuser and lie within the etalon position tolerances.

How much or your local seeing?

Is your house up for sale Mike?, we are seeing a lot of the interior and the garden.

Well regarded achromats in the small range are anything by Vixen F10 and longer, also the venerable Tal 4" F10. Other 4" long focus achromats also have a good reputation. The common theme is long focus, however once you get up to 6" aperture and above, the potential performance is a trade off against the mounting problem. With the current popularity of APO's there is little incentive for manufacturers to service a niche market. I've made a number of 6" and 8" F20 folded achromat refractors, they work very well but despite the relative compactness they still required a substantial mount.

Good heavens Gina, at first glance I thought it was your first solar imaging attempt!

The original configuration was for the inclusion of a binoviewer which required a Barlow to reach focus. The surprising side effect of this was the increased field of view of the eyepiece in conjunction with the 5mm blocking filter as well as better performance. (The "how and why" of this is currently a subject of debate). As a binoviewer is not being used at present, an extension piece takes the place of it.

Practical is better than theory.

When I had the chance to use the 1.25" Lacerta it was on a 220mm refractor. It did have an ERF fitted but it was a transmission rather than reflection type so the heat attenuation was not a great amount.

Pleased to hear that the BV's seem to be ok. Strange about the packaging box, I can't fathom out how an impact heavy enough to cause so much damage to the case would not have penetrated the outer box. I would certainly hold out for a replacement case in due course.

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.