JTEC

Alan, I have the 22mm T4 and it’s one of my all-time favourite eyepieces both in my current refractors and in the 12 and 14” Dobs I used to have. Friends seem to like it too, including some who don’t spend much time looking through telescopes. Really just to say that, imv, it’s a super eyepiece and you couldn’t go wrong with it in terms of quality and performance. Expensive though. I suspect you knew all that already 🙂. I’ve not used the SL, so can’t, I’m afraid, offer any comparisons.

Done, and thank you @laser_jock99 for bringing this to our attention.

Always assuming the light path doesn’t raise issues with focus in your scope, the advantages are all with the 2” I think. First, as Stu and Louis say. And you’d regret getting rid of your favourite eyepiece - why would you do that? I did that once - it was a 22mm Nagler - regretted it and eventually bought it again. I’m struggling to think of any disadvantages of the 2” over the 1.25”. A bit heavier, which really shouldn’t matter. The 2” gives you options. I have had both but only use 2” prisms and mirrors in my scopes now. Those are the Baader prism and the Baader BBHS mirror diagonal, which are, admittedly, high end models - there is no visible performance difference that I can see compared with the 1.25” versions. I like the robustness of the larger model overall and also at the points where it interfaces with the scope and with the eyepiece.

Mark, may I pass on to you a fable that has been of value to me over the years when making choices in a multifarious field? Long ago I was playing around with big cameras, the sort where you put a cloth over your head to view the image on a ground-glass screen, amusing myself doing landscapes. I fancied that I needed another lens and went into a store that sold high end photo kit. Behind the counter stood a pasty youth with - sign of the times - plentiful gel on his hair. This could be a waste of time, I thought. ‘I’m looking for another lens’, I said, ‘but I’m not sure which one to go for.’ ‘Well sir’, replied the pasty one, ‘it depends entirely on what you want to achieve.’ I draw on his unexpectedly wise words to this day and always when buying a lens, an eyepiece, etc - the choices in our hobby are vast and so are the lures and temptations. Reading your posts - and please don’t take this the wrong way - I feel that you still need to clarify and simplify. Exactly what is it you want to achieve? Planetary imaging? DSO imaging? Wide-field or other? General visual observing? All of the above? To quote another even more ancient proverb: no one type of scope is best for everything and all have limitations. Opinions differ as to what scope for what. The best steer, imv, is to look at what the best practitioners are using. I know that fine planetary images are being produced with Newtonians but Damien Peach, by common consent the best planetary imager in the world, has always used SCTs. Fabulous wide-field images are being produced with small refractors - and, having done lots of it, imv, that’s the best place to start with this kind of imaging - the longer focal length stuff is more demanding in every respect. However, a small or even a middle sized refractor is not the best choice for planetary or lunar imaging because, at the sizes we can afford, such a scope won’t have the aperture to resolve the available detail and, usually, the image scale will be too small. For general visual, a small refractor (which I think you already have) for wide field views plus a medium sized (8-12”) Dob. Having owned big Newts and several EQ6 mounts, I think a big Newtonian OTA on one would be a bit of a handful, not just to manhandle but, more importantly, to get to perform optimally - too much to wobble about. Not impossible to achieve, but requiring a heck of a lot of attention to detail and offering lots of things to frustrate and go wrong. Please heed the words of Confucius from the camera store … 🙂 Good luck!

@Flame Nebula Hi, yes, I was satisfied with the views visually. Both scopes were good with the binoviewer, which, fwiw, is my preferred way of viewing Moon and planets. The views, of Jupiter and Mars, for example, were not ‘mushy’ and showed good clarity, colour rendition and detail. The MTF curves I’ve seen would suggest that the SCT might have slight advantage over equivalent unobstructed aperture with high frequency detail but be slightly disadvantaged in the mid range, which, other things being equal, might make it a better choice for some sorts of target than others. The 140 apo image is subjectively nicer to look at and probably samples the available UK seeing almost all the time. When I decided to ‘rationalise’ my kit recently, it was the SCT that went - the apo wasn’t going anywhere. I’ll PM you about the bench test, because a third party is involved - suffice to say, it was done for me by someone whose name most users of the forum would recognise as highly expert and who is a friend. As far as I know, there is no option available to test SCTs before purchase. I had it tested purely out of interest. Please bear in mind that while the SCTs I owned turned out to be good - I’ve heard that quality is more consistent these days - there might still be some ‘less thans’ out there. My feeling is that if you have doubts, it would be better to look elsewhere and many helpful suggestions have been made 🙂.

I’ve owned the 9.25 and the 11 and was pleased with both. I’m a fussy observer and have a TEC140 to compare them with. While the character of views through the apo was (and is) uniquely attractive - there’s no disputing that high quality apos render sweet views - both the SCTs resolved and showed finer detail on, for example, the Moon - not surprising, given their substantial aperture advantage. Both SCTS were good scopes optically and mechanically and this was confirmed for the 9.25 by an expert independent bench test. I’ve had, from memory, 9 Newtonians over the years, from 6 to 14”, including examples with optics by Hinds, Hysom and Grubb Parsons, and would not say that, aperture for aperture, the optically very good Newts generically outperformed the SCTs. There are so many contributory factors, some intrinsic to the design, some to do with the way different sorts of scopes need to be managed in order to perform at their best. And, of course, there’s sky quality to contend with, which doesn’t affect SCTs more or less than any other sort of scope. I liked both of my SCTs. Perhaps I got lucky. Both were rewarding scopes that gave good images and provided decent aperture in a compact package that wasn’t unduly demanding to mount. The AZEQ6 was a good match, incidentally, as was the AZ100.

I’m happy with my TEC which is why, several decades and tens of scopes later, it’s one of two I still have. I’ve always wondered about a Mewlon though, I like the sound of those - optical quality, etc, etc, and, of course, its first name begins with ‘T’ 🙄

Following a recent cull of scopes that didn't get much use, just 2. I call this ‘rationalisation’ but deep down I know it’s just clearing the decks to speculate about what I might get next. For now it’s: TEC140 apo and Stellalyra 90mm apo. Gone for now are the SCTs and big Dobs, but I know they’re all still out there, waiting …

Just on this point. I’ve owned this combo and would advise against it. The Evo is a nice mount but overstretched with the 9.25 OTA. The C9.25 OTA was excellent but putting it on that mount was definitely imv a step too far. As you say, there are problems with clearance at higher elevations, especially with, for example, a 2” diagonal in place. This makes binoviewers and other attachments at the eyepiece end more or less out of the question unless you’re content to observe only at modest elevations. On top of that, high power viewing that was well within the capabilities of the very good OTA was badly affected by the wobbliness of the combination - Celestron should have stopped at the 8.

Bill Paolini’s comparison might be of interest with regard to choosing between the 24mm Pan and the ES68: https://www.cloudynights.com/articles/cat/user-reviews/24-26-mm-eyepiece-comparison-r2651 I have the 24mm 68, my only ES eyepiece, and like it. I really wouldn’t describe it as ‘heavy’. 🙂

Has anyone layered rainfall and other meteo metrics onto a map of UK Bortle data?

The skies where I live in Surrey can vary from a (very rare and marginal) 4.5 to a pretty bad 6. So, I think the Bortle Scale has to be viewed as a somewhat useful but very broad brush indicator. Some of the criteria do seem rather arbitrary and situation dependent - the detectability of the Zodiacal Light, for example - and some of the visual tests seem substantially dependent on the characteristics of the observer. Dark Sky maps have some limitations as well because most show light shining upwards and not the appearance of the sky when viewed from the ground with light domes from adjacent towns, etc - though it’s perhaps reasonable to assume that there’s a useful correlation. A simpler way of finding darker skies is to identify population centres and where people live and get as far away from them as possible. Applying this in the UK will take you to places where you usually can’t observe anyway because it will be raining. 🤣

13mm Ethos, 10mm Delos and 9mm Tak ortho pair in the bino (if that’s allowed). That said, I don’t remember a session when I only used 3 eyepieces.

Roland Christen’s advice with regard to binoviewers, choice of eyepieces, GPCs, etc may be of interest - it’s mostly further down the page: http://www.darksights.com/Binoviewers.htm Personally, I don’t go shorter than Tak 6mms. I haven’t got a pair of anything shorter. I think merging anything much shorter might become problematic but also there’s little need - the 6mms with 1.7(more like 1.5) GPC produce about x240 in my refractor which, for almost every application, including lunar and planetary, is enough. I can get more by using a 2x Powermate ahead of the prism with or without the GPC in place, but never feel the need. FWIW, my ‘favourite’ eyepieces in the TEC + Baader Mk V are the 9mm Tak orthos and the 18mm Tak LEs.

@Mumia, not including various unobtainable, well-nigh mythological eyepieces that I’ve never had the opportunity to try, my vote also goes to the Tak orthos for sharpness, clarity, colour rendition, contrast, etc - I have pairs of the 6,9 and 12.5mm orthos and a pair of 18mm Tak LE orthos for the binoviewer. My shortest fl is now the 4mm TOE but it looks as though @mikeDnight, with his interesting and persuasive review, might have cornered me into forking out for another SV 3-8 😬

Delighted that you’re happy with the Vixen you bought from me Mike - but does this mean I have to buy another SV 3-8? 🙃

As @Mark at Beaufort, I bought one of these because it was getting consistently very enthusiastic reviews and was relatively inexpensive. The build quality was instantly very impressive and it was convenient to use - the only handling issue was that the movement, while very smooth, was also fairly firm to the point where twisting it could tug on other bits of the train. But I attributed this to quality fit, and you’d expect it to loosen up with use. In my refractors it gave good images and performed best in the middle of the range. It was not as sharp as fixed focal length eyepieces falling within its range - Tak orthos and a Tak TOE - but that was hardly a fair contest. In my view, it’s not equal in terms of performance to eyepieces like these but, if you like zooms for their intrinsic qualities, I think this is a heck of a bargain.

I’ll just point out that I have an effectively brand new 7mm APM XWA 100 degree eyepiece listed here in the SGL For Sale section 🙂

I speculated that the gradual coming together of colour correction could be explained by progressive, differential cooling/equilibration within the bodies of the lens elements and/or of the 3 elements of the objective in relation to each other - but that could well be complete nonsense 🤣

Hi @Deadlake. About the same as @Louis D says. Perhaps a bit less. But, by then, it’ll have settled down and be as good as it can be. I don’t think I see any pinching; what I’m aware of is that, until the scope is settled, colour correction is not optimal and it progressively improves until it reaches its best point. To be honest though, I don’t tend to scrutinise these aspects. I’ve been looking through scopes a long time and am happy to rely on an overall impression of image quality. I noticed the colour correction aspect when I hastily banged in a high power eyepiece shortly after taking the scope out. It bothered me initially but I watched as the scope gradually settled down and, as it did so, the colour ‘error’ gradually went away.

I have a 90mm f6 Stellamira (by Long Perng) that I bought as a grab ‘n’ go option and to travel with and like it a lot. It gives very nice views of Moon and planets and, given suitable skies, many of the brighter DSOs. Incidentally, I like it a lot better than the Starfield 102 that receives frequent praise on this forum and that I tried before settling on the Stellamira 90. The 90 is a triplet, so one might expect better colour correction and, imo, it has. If you have the neck for it, viewing straight through gives optimal image quality, I found, but it’s pretty tough with objects high in the sky and I for one can’t last that way for long - interesting to try though. Advice I had from TEC scopes was to use mirror diagonals with (their) refractors to avoid unwanted colour, so I do, but even with a relatively short focal ratio like the ones we’re discussing, I doubt you’d see much difference between mirror and prism at the powers most likely to be used. And prisms do seem to have countervailing advantages, like relative freedom for scatter. Bottom line, I really like my 90mm f6 - it’s good quality, versatile and convenient.

Hi Peter, thanks for responding 🙂 I was thinking in terms of a mid size scope - probably a minimalist, ‘collapsible’ Dobsonian of some sort - that I could carry to dark skies on a plane. David made me a nice 12” f6 scope a few years ago, and I had it in mind to float the idea with him but events, sadly, intervened. Given the weight limitations, I don’t suppose a 12” would be possible but perhaps a suitably designed 10” might squeeze in. I’d wondered about a bare bones single pole design but, while keeping the weight down is a challenge, perhaps there are better ideas.

Very much the same reasons as you @Second Time Around 🙂 I used to be with SEKAS too. The Kent skies were darker then and, in places that I know and visit regularly, are still better than anything I’ve been able to find in Surrey. It’s more than a casual question you ask! Though I think of myself as a ‘serious’ amateur (I have plenty of nice kit and have been observing visually and imaging for decades from the UK and prime locations overseas) deep down, it’s a love of the natural world, land as well as sky, that drives me to keep observing - delusions about ‘doing science’ don’t figure anywhere in there at all, I’m afraid. (Help! I’m a stargazer 😬) In the UK, however, natural beauty is increasingly hard to find and unspoiled skies are more or less a thing of the past. Even those places that appear dark on dark skies maps are, when you get there, polluted by horizon glows and light domes from villages and remote towns. The Brecon Beacons, which I’ve known and walked on by night and day for, ahem, 70 years, are a case in point - once pitch dark but now polluted by sky glow from the Valleys to the South which, incidentally, were themselves ubiquitously pitch black when I was a child and all the lights went off at 11. Many people growing up now in the UK have known no natural darkness, so have no yardstick. They will believe that the Beacons, for example, are genuinely ‘dark’. I know that they are not because I have experienced them much darker - we are slipping into a creeping acceptance of the mediocre and rebranding it as good. Rant over, and to return to the question … I do find that, here in the UK, a key component of what gives me reason to get the scopes out and observe is now in short supply. I still do get the scopes out, but what I enjoy most is to be out under a beautiful sky. For many years, I used to image from La Palma and there, as the mounts ticked away and the data was being gathered, there was time to enjoy the visual wonder of natural night. I still have some of the data, tucked away somewhere. But what stays with me is the presence of the sky.

I’d suggest Japanese orthoscopics and Televue Plössls. These deliver ‘top notch’ optical quality - at least in terms of what I look for - at well below the (rather arbitrary) £150 threshold - though not all observers will find them convenient to use. Personally, I wouldn’t go for any zooms, including the much vaunted Svbony 3-8. I bought one and was very impressed until I compared it with fixed focal length eyepieces by Tak and Vixen within that focal range. So it sold it. At the price, though, I agree, it’s an absolute bargain. If you want wider fields of view and more eye relief that the orthos and shorter TVPs offer, you’d have to look elsewhere, of course and, as others have said, there’s plenty to choose from 🙂

Having tried most, I’ve settled on the DGM NPB and the Televue (by Astronomik, I think) OIII filters. I concur with @John that the relatively inexpensive Explore Sci ones are comparatively ineffective.