John

Virtually all modern eyepieces are sharp in the central 50% of the field of view no matter how "fast" or "slow" the scope is. It is in the outer 50% of the field that the distortions can start and the extent of those depend on how well corrected the eyepiece is and how "fast" the focal ratio of the scope is. Some of the distortion is generated by the scope optics and some by the eyepiece. From my experience of using a wide range of different eyepieces in a wide range of scopes I would say that some of the vendors claims are a little optimistic so should be taken as a general guide rather than a precise forecast. The difference between F/5.9 and F/6 is not significant with this in mind.

With scopes, F/5 is considered "faster" than F/6 , F/9, F/15 etc.

Skywatcher equipment is manufacturered by Suzhou Synta Optical Technology Co in China and they are part of the larger Taiwanese based Synta group. As Peter says above, Optical Vision Limited are the official UK importer of this equipment but also import other brands as well. At one point OVL imported the Russian made TAL, Intes and Intes Micro ranges.

Yes but Orion needs to be visible of course ! Messier 42 (the Orion Nebula) is an entirely different type of object from Messier 13 though. Low to medium magnifications are usually used on this target. Don't give up on bright globular clusters such as M13 though. With a 6 inch scope they are rather nice as you develop your observing skills. I often observe them with smaller scopes than you have and enjoy the views. The visual views of deep sky objects such as the above won't rival the images that you see of them though, even those made using scopes similar to yours. Modern cameras, long exposure times and processing can produce results that far exceed what our eye can see though a scope.

I've just been looking for this one with my 11x70 binoculars. Very low here and hardly any stars showing in that region due to LP. Didn't find it

If you use careful focusing, cooled and collimated scope and study for a period of time under a dark sky M13 will show quite a lot of resolution into stars with a 6 inch scope. 100x should be enough but experiment and see what works best for you. 167x might be a bit much unless the seeing and optics are on song but give it a try. If the seeing is a bit unsteady then the resolution into stars does not jump out at you - you need to carefully observe the cluster to pick it out. It is not resolved to the core with a 6 inch aperture but the outer parts should certainly be resolved into a speckling of stars against an unresolved backdrop. I first got resolution of this cluster with a 6 inch scope many years ago. The jump from my 60mm refractor was substantial to say the least ! With my 12 inch dob I find 150x - 200x ideal and the view is spectacular but I have 4x as much light and 2x the resolution to play with.

When I last owned a TV 32mm plossl, I was advised to get a TV eye guard extender to help position the eye correctly. It worked wonders and made the eyepiece a pleasure to use rather than a bit frustrating as it had been previously. The downside is that an expensive plossl had become a very expensive plossl

Tele Vue do a "2p worth" you know ? - top quality of course and the cost is £1.00

True enough. My sky seems to vary between Bortle 5 or even 4 on a really good night towards the zenith and probably as bad as 8 looking towards Bristol or Newport / Cardiff. According to Clear Outside I'm a 5.

Hi and welcome to the forum I have not spent much money lately but I have spent a lot of time on the hobby due to the clear skies. It has been a rather unusual but welcome period, at least as far as our hobby does. Your work in the NHS is very much appreciated by the way I'm pleased to hear that astronomy is helping you to unwind after what must be very intense periods at work I hope you enjoy being part of the Stargazers Lounge !

These are great images I could not find Panstarrs visually, or at least not with any certainty, the night before last with my 100mm frac. I did get it a few days earlier with the 120 but I think it was a touch brighter then. Little proper darkness, even overhead just now, which does not help ! M81 and 82 were clear enough but I think the comet is a more diffuse target.

The tube length is critical as well as it's weight. A light but long scope will overpower a mount even if it is well within the load limit. For a while Celestron used to supply the C5 SCT on the EQ-2 mount as an option.

I've owned and used a couple of the Vixen NPL's and rather like them. I read somewhere that the Vixen design uses a similar lens figure to the TV plossls (which is a slight variant on the standard plossl).

To get a similar optical quality to the Starguiders I think you would need to consider the Baader 8-24mm zoom which cost about as much as 4 Starguider eyepieces. The less expensive zooms are OK but the Starguiders provide better overall performance in my experience. At the 24mm end zooms have quite a narrow field of view so you would still ideally want a fixed focal length low power eyepiece as well as the zoom, say a 30mm or 32mm so the investment needed increases again.

Thats not normal. Normally an eyepiece is fully inserted and the focuser would be somewhere in the middle of it;s range of travel when the scope is at sharp focus on an astro target. Not all eyepieces reach focus at the same place so you need some movement available to be able to use them.

A few years ago the long achromatic refractor was indeed dying out. Over the past few years, influenced by a few articles and publications by authors such as Neil English, an interest in these traditional designs has reignited among some visual observers. So the vintage long refractors became sought after and some newly manufactured units have emerged, notably the 102mm F/11 achromat which Lyra Optics imported from the far east a few years back, Richard Day's composite creations (as showcased by @johninderby above, Moonraker Telescopes and there are a few more options now. If these designs are appreciated, and enjoyed and people are prepared to spend their hard earned money on them, it's good that manufacturers have responded. Choice is a good thing I think

Thanks. That's interesting to know

What scope / scopes do you use it with and how is the edge sharpness ? It is a heck of a lot smaller than the ES 92 / 17 that/s for sure !

26% illuminated this evening. Very beautiful. Set my 100mm Tak up quickly to catch the very skinny Venus before it sank into the hedge. On to the Moon hanging so temptingly in the sky. Highlights include a trio of craggy craters on the terminator, Theophilus, Cyrillus and Catharina. The central peak in Theophilus looks really jagged and shattered in this light. Posidonius further north with it's partial internal second rim which looks as if a major portion of the crater floor has been tilted somehow. 2 / 3 rilles cross the crater floor as well. Lots of geological action here over the aeons. The long wrinkle system of the Dorsa Smirnov running for over 200km across the Mare Serenitatis. Messier and Messier A plus rays nicely displayed again. Certainly made up for the scrubbing of the Falcon launch. Maybe we will get back there one day

I managed to get Venus myself at around 9:40pm. As soon as the Falcon launch was scrubbed I popped my Tak out and found Venus lurking between the soffit of my house and the hedge top ! Nice to observe it for a while - I think this is the slimmest that I've ever managed to see the phase

Great catch Mike According to the Virtual Planet Atlas software the phase is currently 1.8%. With the phase so thin I think it is difficult to catch it accurately when imaged - my shots from last night (2.3% illuminated) were pretty much the same as it looked at 4% or even 6%. I guess there is only so much that mobile phone sensors and firmware can handle ! Your drawings are much more how it actually looks though the eyepiece - very delicate

I have owned a Meade AR6 152mm F/8 refractor and the false colour is quite evident. It's OK for visual observing but I don't think an imager would find it acceptable. Also they are very large scopes to mount steadily. Have you considered putting your 8SE tube onto a sturdy equatorial mount ?

East coast I think. We visited the pads in late Feb on the KSC tour. This was pad 39a then:

I don't think those issues will affect performance of the scope at all. Don't use the Baader fluid on the mirror - it is intended for lenses not aluminised surfaces. I would just get on and use the scope. Look and the mirror clips and central obstruction - they cover far more area of the mirror than any of the marks or the tiny scratch and the scope still performs well.

Sounds like the seeing was poor wookie. Those globulars are usually rather nice even with 100mm of aperture. Sounds like you did still get some nice stuff though Sometimes it goes like that. I could not find Comet Panstarrs last night although it should have been visible with my scope. I gave up in the end and went onto the Cats Eye and Blinking planetary nebulae which were nice to observe and easily found.