JTEC

Thanks, Deadlake - interesting link!

Thank you, Don. That’s tremendously interesting and informative. This feels like (yet) another instance of horses for courses. I wonder if, with the increasing use of blue-rich LED lighting and ubiquitous scattering, that drop of in reflectivity/transmission in the blue might be advantageous in some circumstances and with some targets.

I believe that the ‘prismatic smear’ that Don refers to might be somewhat greater with the 2” prism over the 1.25” because more glass is being traversed? I have both the Baader-Zeiss prisms and like them a lot; much prefer them to the AstroPhysics dielectric I used to own. However, I recently got hold of the Baader 1.25” BBHS and the difference in colour rendition and range is obvious. This is now my preferred diagonal in the 140 f7 apo. I am so taken with these qualities that I began to wonder about replacing the alu coatings on my 12” Dob with modern, suitably protected silver. That’s a different thread I guess. I expect it would be pricey to do but that’s academic at the moment because I can’t find anyone offering to do it 🙂. Any suggestions welcome!

I have Tak ortho pairs in 6,9 and 12.5 and a pair of 18mm Tak LEs. The LEs seem to be a mixed bag. I like the 18s but got rid of the 10s. Like you, I can find no advantage in the LEs over the abbe orthos, and they cost more too. Interesting about the BCO over the Delos - and the BCOs are a fraction of the price at £49 against £336 current FLO prices. Given your experience with them, that has to be some kind of a bargain.

The straightforward answer would be Takahashi eyepieces ... that would also be my suggestion in terms of visual experience for outlay. I’m fortunate to own a TEC 140, which is a refractor in the same quality class as a Tak, and a number of high end eyepieces, including Delos, Pentax XW, Ethos, Morpheus, Tak TOE and Vixen HR. I also own pairs of the a Tak orthos which I use singly or for binoviewing. In their different ways, these are all terrific eyepieces. That said, the sharpest, most transparent views of solar system objects and DSOs are, albeit marginally, with the Tak orthos. They’re also the cheapest. The TOE and HRs are also excellent, but using them takes you to small exit pupils and places where other factors like seeing, etc are more intrusive, and it becomes more difficult to make definitive comparisons. That said, I find the performance of the Tak orthos ‘Barlowed’ with Powermate closely comparable to that of the unbarlowed TOE and HR. For middling focal lengths, of the eyepieces mentioned above, for sharpness and transparency, I’d put the Delos second behind the orthos but only very marginally ahead of the rest. Until recently, I swore by the Baader Zeiss spec prisms and I still think these are exceptionally good - clearly better than, for example, the William Optics and AstroPhysics dielectrics I used to own. I’ve just been testing a Baader BBHS (silvered) mirror diagonal though and I think if I could only keep one diagonal it would be this. So, my straight answer to the OP’s question would be: Tak orthos and 1.25 Baader BBHS mirror diagonal. I’d also suggest planning for a decent binoviewer when the budget allows because, for solar system viewing especially, that will transform your observing pleasure and effectiveness more than the difference between any two eyepieces of even broadly comparable quality.

From Tom Trusock’s 12/07 Part II of IV Report on Nagler Eyepieces on CN. I suppose if anyone knows the answer to this, it would be Televue: ‘As an interesting side note, I asked Tele Vue if the infamous "Eyepiece Cool Down" myth holds any water in the real world. Their answer? Nope. There's no cool down effect for eyepieces. The only "gotcha" that might exist here is that massive eyepieces could cause some visible tube currents is taken from a warm house out into the cold. Specifically Tele Vue says: "the eyepiece is in such a low power-space that it is impossible to see any image change due to thermal changes of the lenses. This myth seems to revolve around the 31mm Nagler which produces low power not suitable to observe changes in performance due to equilibration of the optics. "’

I’m not sure it’s helpful to frame the debate this way - but it is your question and I know what you’re getting at. I have a pretty eclectic bunch of eyepieces including a 13mm Ethos, 8 and 10mm Delos, 5 and 7mm Pentax XW and pairs of the Tak orthos at 6, 9 and 12.5mm to use mono or bino. The wider fields are all ‘sharp’ with, to my eye, the 10mm Delos being marginally the sharpest and most transparent, followed by the 8mm, and the other three differ more in character than in quality. The orthos are perhaps a teeny bit sharper than the best of the ‘wide fields’. But here’s the thing, I think, the modern wide fields - at least the ones I’ve mentioned - are all so good that in actual use sharpness and contrast do not present as issues. I know the Ethos maybe isn’t quite as sharp as the Tak orthos and I know the Pentaxes show colour in a way the orthos don’t but the differences are inconsequential when set against the other experiences these excellent eyepieces offer. And it is about options, I think. You can take in M42 with a longish Ethos or dig into the Trapezium with a shortish ortho. Both are valid and distinctive observing experiences. There is a lot to be said for doing both at a session because, even allowing for differences in spec, eyepieces often give surprisingly different renditions. I found a world of difference, for example, in the presentation of Mars last year when viewed through the 2 Pentaxes, the 6mm Tak ortho and a 6.5mm Morpheus. Some would say you can have the best of both worlds with, for example, the short focal length Ethoses. In the interests of debate, if I had to choose from the eyepieces I know one range to stick with, it would be the Delos. But I’d rather be allowed to keep a varied and versatile toolkit. And incidentally, I think that might involve resisting the psychological pull towards building complete sets of any one model or range.

One more for the Televue Powermates - superb optically and mechanically, pretty much invisible in the train.

I have wondered the same thing, Louis. BillP’s review of the BBHS made it sound very tempting. I’d like to give one a try but can’t justify the expense of doing so.

Both Baader-Zeiss prisms perform beautifully in my scopes (TEC140 and C11) at all useable mags. Visibly less scatter than the ‘best in class’ AstroPhysics Dielectric I previously used, and sold. No discernible unwanted colour whatsoever at these focal ratios (f7 and f10). Work perfectly with binos, where same applies. BillP seemed to prefer the 1.25 prism slightly over the 2” for planetary views. Can’t say I really notice any difference; that said, my best ever planetary views have indeed been with the TEC, Zeiss-Baader binos and the 1.25 prism.

Both seem to me to have the capacity to take your scope to unexpected levels and show what it can ‘really’ do - at least, on the Moon. Barlowing them is interesting : )

They’re fantastic aren’t they! I have only the 4mm TOE and the 3.4mm HR and use them in a TEC 140 - don’t think the shorter ones would get much use. I’ve tried to characterise the differences between them. I’d agree with your word ‘smoother’ for the TOE. Perhaps paradoxically, the ‘smoothness’ doesn’t seem to entail any loss of available detail though.

I bought a C11 because I wanted an affordable step up in aperture from my TEC140. I also have a 12” f6 Newtonian which is great optically but more awkward; the C11 is stubby, convenient, portable and has the advantage over the Dob of working well on my AZEQ6 enabling easy goto and tracking. I also had ideas of doing some planetary imaging ... which, of course, I never got round to doing! The refractor is the scope I’d never give up because optically and mechanically it’s as good as it gets and it delivers special image quality. I am a fussy observer and I was prepared to be underwhelmed by the SCT but, on the contrary, I’ve been favourably impressed especially on certain targets. Optically, it isn’t bad at all. Its greater aperture allows it to easily outperform the TEC on the Moon - a high contrast target, of course - resolving finer and showing more detail. It performs very well with the binoviewer, especially on the Moon, globs and many compact nebulae and will take high mags on subjects like these. Collimation is easy and holds very well. Some minor image shift is discernible from time to time on focusing but, with modest focus changes, I've not found this to merit the fuss that’s often made about it. Perhaps I’ve been lucky with my particular example. I did fit the Baader Click-Lock back in place of the Celestron original, and that’s an improvement worth making I think. I use it with the Baader prisms. In a real world where 11” apos aren’t an option, the C11 fills the gap I wanted to fill and, in the event, performs better than I’d expected. .

Just to support and concur around the 17.5 Morpheus. It’s one of a few eyepieces in my rather randomly accreted collection - that includes, among others, an Ethos, several Delos and a couple of Pentax XWs - that I think is outstanding and really wouldn’t want to lose. The others I feel the same about are the 10mm Delos, the Tak TOE 4mm and the 3.4mm Vixen HR. I like the 6.5 Morpheus a lot as well, very sharp and comfortable to use.

Plus 1 for orthos. I’ve found the 6.5mm Morpheus to be excellent on Moon and planets. Relatively wide field, easy eye relief and not crazy expensive. In this sort of range, I also use the Pentax XW 5 and 7mm, the Tak 6mm ortho, the Tak TOE 4mm and the Vixen HR 3.4. They’re all, IMO, superb eyepieces that differ more in feel and character than objective quality. I’ve been using and comparing them all on Mars lately in my 140mm f7 apo; the 6.5 Morpheus definitely belongs.

You’re right, there’s not much off axis to be had! 😂 They’re a bit quirky and known for the famous ‘floating image’ effect. I like them and they go down well, I find, when showing people things through the scope. I don’t think anyone would suggest choosing them in preference to, say, a pair of 24mm Pans though. That said, they are the fraction of the price and a lot of fun to use. The RKE range as a whole has slipped off the radar and something is being lost, I think. These are very sharp, bright and contrasty eyepieces that In the shorter focal lengths work very well on Moon and planets and, apparently, were once very popular in that role. I had the 12mm Barlowed alongside a 6.5 Morpheus, a 6mm ortho and a 5mm XW on Mars a few days ago. All of those eyepieces gave great images with each contributing something of its own character that distinguished it from the rest, including the RKE.

I agree about the Delos being a bit hefty when paired, so not first choice despite their optical excellence. Also using a TEC140 and Baader Mk V and just for interest, the pairs I have are: Tak orthos 6, 9, 12.5, Tak LE ortho 18, Sterling (Long Perng) Plössl 20 mm and Edmund RKE 28mm. Used with x1.7 (giving about x1.5) GPC or x2 Powermate. I’d say the 9mm orthos get most use but if I had to pick one pair it would be 18s and vary the negative lens. As you say, eyepiece preferences are personal though.

You might like to include the Morpheus range in your options to consider. Supposedly these were designed with binoviewing in mind. I’ve tried pairs of these and of the Delos, and they both work fine. Both excellent as singles, of course. For some reason, I’m more comfortable with narrower fields than these for binoviewing. Orthos work well for me, as do the TV Plössls, but it sounds as if you’re looking for more eye relief than these generally offer. I really like the pair of 18mm Tak LEs that I use, and these have more generous relief. If I could keep only one pair it would be these.

John, I have both the 2” and the 1.25. I use them interchangeably in my TEC 140 And C11 (just the 2” in the SCT). I also have the Baader 1.25 mirror diagonal but that doesn’t get used much because, IMO, both prisms are better in terms of contrast and scatter. The eyepieces I use are typically high-end: Tak orthos, Delos, Ethos, Tak TOE and Vixen HR and sometimes push the magnification quite high, so the prisms are being given a decent test. I use the smaller prism with the bino when using the Baader glaspath compensator in the train and the 2” when using it with the 2” TV Powermate instead of the gpc. I’ve read (and re-read) Bill P’s report. In practice, I can’t honestly see any difference in performance between the two prisms - and I’ve often gone looking for it. If there is a difference, it’s likely to be just one tiny variable among many. I do think that both have a clear edge on the mirror version though. I’d like to try the BBHS mirror that BillP enthuses about, but it’s too pricey to buy just to find out. I have been told that both of the Zeiss Baader prisms have the BBHS coating on the hypotenuse - I’m not sure why though or what contribution it makes. Both prisms outperform the Astrophysics dielectric that I used to have - when I compared the views, the Astrophysics, top quality mirror diagonal as it is, went up for sale. Summing up, I don’t think you can go wrong with either. In practice, I tend to use the 2” a bit more because, with the excellent Clicklock system, it is so convenient and gives up nothing in quality that I can see.

Ah, that would be the OOUK AG, presumably ...

Agreed. It sounds as if you have access to some good dark skies ;>) I understand what you say about textured background - from the darkest sites I’ve visited, lying on your back scanning the MW through Cygnus, say, gives an impression of continuity. Not always easy to separate scattered starlight from nebulosity, I find, at least without filtration. 200mm f3.8 sounds interesting!

Just caught your interesting post on the Tulip. I’ve not observed it visually but here’s a H-a pic I took of it some years ago with a 98mm scope, really to show some of the context - just look at all that stuff in the same field.

Totally agree. Tried all the usual suspects over the years (Lumicon etc) I honestly think the Televue OIII beats them all. FWIW, if I had to pick one UHC filter for general use it would be the Omega NPB.

Unlikely, to say the least.

The 12.5 mm Tak orthos (though not so much the LEs) I find to be very sharp, contrasty and relatively affordable. I have a pair for binoviewing. I also own some Delos, Morpheus and Ethos eyepieces and all are, of course, excellent in their own way. If I had to choose from those 3 for optical quality, it would be the Delos, though I think there is very little in it. Best value of the 3, the Morpheus. The sharpest eyepieces around that focal length for lunar detail that I own - and to my eye in my scopes - are the Tak 9 and 12.5 and the 11mm Televue plossls which make an exceptional planetary binoviewing pair with my TEC140 and Baader MkV. In this regard only, I would put both a bit ahead of the Ds, Es and Ms - though, of course, those eyepieces have other qualities that might tip the balance for you. Fact is, we’re spoilt for choice ;>)