JTEC

I owned the Kasai widebinos for a while and wrote a short review - reference below, and there is other discussion on here if you search. They are interesting and nice to have but, a personal view, I wouldn’t see them as a solution to any visual issues you might have. As Peter says, how well they worked for you would depend on the nature of those issues, something I’m not qualified to comment on. The eyepieces are individually adjustable for focus. Being of Galilean design, there is quite a lot of distortion in the outer parts of the field and chromatic aberration was evident. Overall recollection is that they were worth having especially for sweeping dark skies but not quite as immersive in effect or as intuitive to use as I’d hoped. Kasai WideBino 2.3 x 40 mini review By JTEC, September 27, 2018 in Discussions - Binoculars

I thought that the Televues were made by Astronomik and essentially identical to the Astronomiks, Televue claiming to select to meet their own supposedly uncompromising standards. Certainly the recent TV OIII filter I have is excellent and very tight. That said, and I’ve not put it to the test, but I bet you’d be pushed to notice any difference between the straight Astronomiks and the ones made by Astronomik for Televue.

Just to chip in: I’ve tried most of the well-known UHCs over the years and ended up favouring the NPB. As for OIIIs, I think the Televue (by Astronomik) is exceptional, best of the bunch to my eye, and that includes Lumicon etc. But then, as John says, there is an element of personal preference in these choices and the subtly different renditions they give. Though not in the same league as the above, the relatively inexpensive Ex Sci filters I thought were decent value and an inexpensive way of gaining some idea of what such filters do.

Thanks Louis! Will do. John E

Yes. My point was really prompted by hearing the ZAOs consistently lauded as unmatched by any current production eyepiece and wondering why, with the advances we’ve seen with glass, coatings, etc, this was still the case. For example, in his review of 24-26mm eyepieces, Bill Paolini gives the ZAOs straight ‘A’s for contrast/resolution/transmission on a range of solar system and deep sky targets, with no other eyepiece, including many respected ones, coming even close. And his view appears to be shared by many other similarly expert observers who know what they’re talking about. Granted, there are subjective as well as objective differences due to design, materials, production quality, etc, between eyepieces that lead to subtle (or sometimes gross) differences in observer experience, not to mention matters of individual preference that further cloud (oops! bad word!😖) the issue. But the ascendancy of the ZAOs - in terms of the package of observer experience that they reportedly gave - still goes pretty much unchallenged. It can’t be the case that with current technology it is no longer possible to produce such character and quality. So it must be that the will - or, realistically, the market - is considered to be no longer there. Or maybe all that polishing is soooooo expensive. Or we are being pushed by marketing to favour optical tours de force like the Ethos series over pure ‘classical’ excellence. Hmmm ... can of worms detected ... most of my eyepieces are Ethos, Delos or otherwise by Televue, by the way, and I think they’re outstanding. But I’ll just note that the 21mm Ethos is currently priced at £816 and, knowing that not everyone wants or even likes 100*, query why a structurally much simpler eyepiece of ZAO quality could not be made and sold for considerably less.

Oh crikey 😐 ... now vanishingly rare, presumably. Bet there are a few forgotten in dusty attics. But not on eBay.

There was no side to my question 😊. I’ve never seen a review that says something like ‘The ZAOs performed well but were bested at all focal lengths by the Super Star-Munchers’. The reputation of the ZAOs as The Best appears unassailable and is upheld by people who should know and are in a position to make expert comparisons. I’m not - I’ve never looked through one - but I’m happy to accept the consensus of the clued up people who have. But we’re not talking about a Stradivarius or an art-work by Picasso. These are objects built to a formula from metal and glass with a whiff of something or other for coatings, etc. They contain no magic, only carefully selected materials and excellence of form and manufacture. And yet, while there have been advances in eyepiece technology in the 25 years or so since the ZAOs were made, they have reportedly not been equalled let alone surpassed. So, my question boils down to: ‘Why not’?

I doubt this one will ever run out of mileage 🙂. I’ve used the UO orthos, some of the shorter BGOs, the odd Fujiyama and all of the BCOs and now have the Taks 6, 9 and 12.5, the last two in pairs for binoviewing. The UOs were too long ago to compare with. My recollection of the BGOs is, like that of other users, very positive. I had a 6mm that I really liked for its good contrast and sharpness, so, naturally, I sold it ... why do we do this?! 🤔. I think the BCOs are great value but, speaking personally, not quite as good and I don’t like their feel and construction. The current Taks, in my view, are comfortably as good as any of the above and are the best high quality ortho option now available and, like all the Tak stuff I’ve experienced (I have the 4mm TOE) of unsurpassed overall quality and build. That said, I’ve read over and over and over again and thereafter ad infinitum about the legendary magical qualities of the true ZAOs and how they outshine each and every ortho made since. And this from people well qualified to make the assessment. Why is it that with the continuing progress in coating technology etc, this is still the case? I know about ‘polish’ etc but Televue eyepieces, for example, don’t exactly have the finish of a frosted bathroom window. The ZAOs were made, I believe, about 25 years ago. Unless we’re to settle for vague romanticised explanations about ‘the lens maker’s art’ and the like, their objective qualities are presumably analysable and quantifiable. What’s stopping equal quality from being produced and on offer now?

Hi Space Hopper. It’s a great combo isn’t it. I use the Baader prisms as well, having tried most other options - I’ve not found anything better and the Clicklock system is a real treat. I’ve used the 1.7 GPC (which reportedly gives more like x1.5) more than the others. I think they all work very well. You might think, as I did, that the Powermate (since you have one) is worth experimenting with. I haven't decided whether I think it’s ‘better’ than using the GPCs. It is nice and solid. With the PM, the TV T adapter lets you screw it direct to the bino - you unscrew the black section of the PM. As for eyepieces, I have some pairs of the Tak orthos which work well and I like the 18mm Tak LEs; also a pair of 28mm RKE’s which are a bit unusual but give those bright ‘floating’ views. If I had to pick one pair, it would prob be the Tak LEs.

I’ve found the brighter DSOs to be superb binoviewing targets. I’m not sure it would be the best approach searching for seriously faint stuff, though perhaps the advantages of the two eyed approach - you do see more - might compensate to some extent for any light loss. For brighter objects, the light loss argument can, in my experience at least, be dismissed. I’m not saying there isn’t any - I’m saying it’s negligible in terms of observational impact. I’m not talking about big aperture either. My scopes are a TEC 140 and a C11. The binoviewer is a Baader Mk V. The binocular views of, say, M42 and M13 are dramatically more engaging than the mono views. For the Baader at least, I believe that a negative lens is required to lengthen the focal ratio and diminish the chromatic aberration due to the prisms. This, I think, is what Roland Christen said, and he designed the unit. I started with the GPCs but now use the 2x Powermate; there are other options from Baader and AstroPhysics. There is no problem about using such a lens. There is no degradation of the image. In fact, because of the above, it is arguably improved. On top of this, it allows you to use longer focal length eyepieces which, in most cases, are likely to be more comfortable. By the way, I suspect that the Morpheus you’re using is one you bought from me. 🤔 I hope it’s going well!

I would like to propose that most lamp posts be dismantled, sawn in half and the pieces put to better use in the kind of way you describe. 🙂👍🏻

Mike puts it perfectly, imv. Using binos on, say, a 10 inch scope absolutely does not reduce its performance to that of a 5 inch. The resolution of a 10 inch aperture is retained. Of course, the light is split but the information it carries is integrated by the observer and the resulting image is significantly more detailed with, to my eye, only minimal loss of perceived image brightness. With lunar and planetary, as well as brighter nebulae, globs and open clusters, the latter consideration is simply not an issue. Having to use a Barlow ahead of the viewer is no real disadvantage. It means, among other things, that generally more comfortable longer focal length eyepieces can be used. I think that Roland Christen recommended not going below 10mm - the advice is widely cited. I’ve not found any advantage either in apparent fields of view wider than about 60*. Though they’re much touted as bino friendly, I personally didn’t like the 17mm Morpheus to bino that much - though I like it a lot in mono and keep one. My ‘favourite’ bino pair are probably 18mm Tak LEs with a 2x Powermate ahead; I’ve also had great planetary views with 11 and 8mm TV Plössls and a 1.7 (>1.5x) Baader GPC. For wide field viewing I’m happy with mono. I think you just have to give it a go! No need to break the bank, there are some good values out there, new and s/h and you can always sell on if you don’t like it. Until you try, you’ll always be wondering ... 🤔

They add a new dimension to lunar and planetary observing, as many have said. Don’t assume though that they’re no good on DSOs! M42 is utterly spectacular and indescribably immersive. Brighter DSOs like M27 are also enhanced, as are globs and open clusters. You’ll never look back. It helps that expensive widefield eyepieces are not required. My preference is for orthos and Televue plossls down to about 8mm. I once tried a pair of 13mm Ethoses (not both mine!) and while the view was spectacular it was also quite confusing. People sometimes report that they can’t get the hang of binoviewers. I’m convinced that this has nothing to do with any special skill - imv, if you can use binoculars you can use a binoviewer. Problems arise I think when the bino isn’t accurately collimated, interpupil distance isn’t spot on and exact differential focusing can’t be achieved; also, if eyepieces can’t be orthogonally seated and held truly on axis when rotated to achieve focus. These are constructional issues to do with the particular bino being used and nothing to do, imo, with any mysterious binoviewing skill being required. In fact, once the set up is good, binoviewing is wonderfully relaxing, floaters are less obtrusive and, thanks to whatever the brain does in terms of combining the data from two eyes, you see more. I should add that my experience has been with refractors and a C11; never tried them with a Newt.

I’m fortunate to have the 4mm TOE and the Vixen HR 3.4 - both are exceptional optically and in overall build. There have been discussions around this in the forum to which I’ve contributed along with others in some detail. Someone commented along the lines that at last he’d found an eyepiece (think it was the Vixen) that could show what his scope (100mm Tak?) could really do. That summed it up perfectly I thought. My main eyepieces are Tak orthos, the point being that I have those to draw comparisons with - to my eye and in terms of what’s currently available, both the Vixen HR and the Tak TOE are about as good as it gets. And, yes, given their short focal lengths, I find both remarkably comfortable to use.

Just for interest, there’s some more discussion of these following my short review listed in this forum dated Sept 28 2018. I liked the concept. They were fun to use but the conditions where I live were a bit limiting. I think they’d really come into their own somewhere dark - Stu’s idea of using filters could also be very interesting at such a site. Despite the relatively small size and weight, the balance and ergonomics are unusual - they really need to be ‘as one’ with your head to get that seamless Supervision feeling - It sounds as though you’re working on it! No bolts or glue though, please ... 😖

Agreed. The weather we have here at the moment is perfect for reading reviews ... 🌧

Well, I think it’s fair to say that you’ll never ever need to fork out for an upgrade because the Zeiss prisms are as good as it gets. If there is anything better, I don't know what it is. Before purchasing mine, I took note of BillP’s reviews. After my own tests, I felt that, as with most things, he was right on; that’s still my view. Off went the Astrophysics dielectric to astrobuysell. And, as a convenient plus, you get the Clicklock mechanism. ATB John E

Viktor, the scopes are TEC140, f7 triplet apo and C11 f10 SCT. I use the prisms mono and also with Baader MkV bino. Actually, I only have one 2” eyepiece now (ES 30mm 82*), so, for most things I’d be entirely happy with the BZ 1.25 prism. The 2” prism gets used, of course with the 2” eyepiece, but also when I put a Televue 2x 2” Powermate ahead of the binoviewer. If I’m not using the Powermate, the 1.25 prism - which has a relatively short light path - works with one of the Baader GPCs (usually the x 1.7 > 1.5) very well indeed. Both are mechanically robust and the Clicklock fittings I find to be a delight to use. BW John E

Viktor, I have both the Baader Zeiss prisms. BillP gives a slight nod to the 1.25 over the 2” but I’ve never found myself swapping the big one out and the small one in in pursuit of improved quality ... both are excellent. I haven’t used the non Zeiss Baader prism so can’t comment on that. Other diagonals I’ve used include the Baader t2 mirror, the AstroPhysics dielectric and a William Optics dielectric. The WO and Baader mirror performed to my eye on a par with the AP, with perhaps surprisingly maybe a slight edge with these examples to the WO, but both the Zeiss Baader prisms, imv, clearly outperform them all in terms of contrast, brightness and freedom from scatter. If you could stretch to the 2” Zeiss Baader, you’d be assured, I think, of unsurpassed quality and be covered for all future eyepiece options etc. There’s no difference that I can see which should push you towards the 1.25 rather than the 2 on performance grounds, so imv the choice would be down to affordability and intended use.

Astronoam, why not put up a wanted ad for a decent s/h 4mm ortho then, such as the ones by Astro-Hutech? Or shorter if that is your intention? Afaik, there’s not really anything sharper that’s both affordable and available. Good luck with your search.

You said that the 6mm eyepieces don't work well with the Barlow - perhaps there’s a technical/optical reason for that but just as likely, imv, perhaps it’s because, with the equivalent of a 3mm eyepiece in there, you’re pushing the magnification too high with your scopes and conditions especially on those targets. I think timebandit has it right on this. And I think John’s idea of a zoom could be a really useful one and help you clarify just how far the mag can be pushed on different targets before quality begins to decline and extra ‘power’ becomes counterproductive. This would also help you determine whether a shorter focal length eyepiece is really what you need and, if so, how much shorter it’s reasonable to go.

Could I ask why you are ruling out the Barlow option? Barlows have a number of advantages not the least of which is to allow the use of longer focal length eyepieces which, generally speaking, are going to be more comfortable to use than, for example, shorter orthos than the ones you have.

Apart from incidence of clear nights, potential relative freedom from light pollution and the possible advantage of a higher altitude site, there is the elevation in the sky of imaging targets to consider. By heading south from the UK, popular southerly targets like, say, M20 and M8 are higher in the sky which means less air mass and UK grime to image through. Add to that that some of the more southerly objects that are inaccessible from the UK become available.

Well, I keep mine in their original boxes with the end caps on and carry them about in those inexpensive plastic toolboxes you can get at B&Q. This is a rather primitive approach when compared with bespoke cut out cases, etc, but it does keep them totally safe. Some of them are quite expensive; some have vulnerable eye and field lenses - the last thing you want is damage to these. You also don't want dust and damp getting in on the act and you do want to minimise knocks, scratches and the need for frequent cleaning. When I’m observing, I’ll sit them back in their boxes with the end caps on but leave the boxes open. So, you’re safe buying a used eyepiece from me 😑; it won’t have been dropped, kicked around or left to fend for itself in some dusty cupboard somewhere. That said, if yours are worth 75p, sling them in an old sock with some gravel and give them a good shake 🤪. But I bet they’re. worth much more than that and as others have pointed out, some inexpensive eyepieces perform well and are worth taking care of.

I know what you mean ... I had a pair of the 10mm LEs, sold one kept the other. Good but not exceptional ... not cheap either! I do find that the 18mms are great for binoviewing though, probably my most used pair (with Powermate or GPC up front) - sharp, not too wide, comfortable but not excessive eye relief.