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Brandon Vernonscope 94mmF7 APO first impressions.
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Brandon Vernonscope 94mmF7 APO first impressions.
Hi all,
I recently took possession of a 94mmF7 APO refractor made by Brandon Vernonscope.
I had done a lot of research on these scopes before making the leap (more like a cram internet session while the scope was still available.) and I found various and sometimes conflicting opinions.
So, I thought I’d post some first impressions while they’re still recent.
The thing that sold me on this scope, despite its age (1980s) was the fact that its objective is a cemented triplet APO lens made by none other than Roland Christen of Astro-Physics fame. The rest of the scope is essentially Unitron, which is not a bad thing. Unitrons were the epitome of the long refractor age before Don Yeier of Vernonscope came along with this scope and turned accepted refractor doctrine on its head.
In fact, as Dave Trott explained in one of his videos, this scope marked the inflection point where the long F15 refractors (long F ratios to combat CA) gave way to much shorter and manageable ‘short tube’ refractors with equal to or superior CA correction. The Vernonscope 94mmF7 was the scope that started this APO revolution.
And only approx. 500 of these scope were ever made..
So what is it?
The Vernonscope 94mm is an F7 triplet APO refractor. And while it was revolutionary in its day, I have read many reports that criticize this scope because it can’t keep up with modern APOs.
Well, duh.
Multi/dielectric coatings and FPL-53/fluorite glass simply did not exist at the time, but despite that, Roland Cristen managed to design a triplet lens that came pretty close, even by today’s standards. And there is no substitute for the exceptional polishes and fine figures of Roland’s objectives. They go a long way to making up for the deficit that modern coatings and glass present. As I’m sure Roland would agree, it’s a lot easier and cheaper to deposit 99% di-electric coatings and claim the use of ED/Fluorite to flout your product than it is to put the time and effort into creating an exceptionally figured lens.
It uses an ‘old school’ (ie: not a Crayford) rack and pinion (my preference) Unitron super focuser with 2-1/4” of travel. This combined with a sliding drawtube which is itself capable of about 6.5” of outfocus means this scope can focus from infinity down to about 10ft.
The extension tailpiece will accept 2” accessories so it is fully compatible with today’s accessories. If you remove this tailpiece (why?) then the ID of the actual focuser body is 60mm (2.36”) which may have led to some of the comments read on-line criticizing the non-standard focuser dimensions. Bottom line is – don’t remove the focuser extension tube. If you bought one without the focuser tube, then you either have to find one, or make an adapter. And without this focus extension tube, you will not be examining ants on your peonies… As an interesting aside, as Dave Trott also demonstrated, because this is a Unitron focuser, it will accept Unitron accessories – like the Unihex rotating EP holder. It just slides right in in place of the extension tube – I just have to find one.
And despite non-marring EP accessories being all the rage now, Unitron had this figured out 50 years ago. Their extension lock and diagonal lock are clever non-marring designs consisting of a bendable ‘tongue’ which bears against the extension tube or diagonal and whose tension can be adjusted with a thrumbscrew.
I admire the ‘old school’ design aesthetic. It is usually robust, well-made and precise. There is something to be said for handling something that was conceived and manufactured to high standards before CAD software, CNC machining, anodizing and 3D printing became the norm.
First impressions
- It’s bigger than what the photos convey.
- It’s very Unitron-like in its aesthetics. It should be as it’s basically a Unitron OTA (albeit a shorter one)
- It’s hefty. I had forgotten what a 10lb telescope weighs…. I have found that the only true light refractors are Borg’s (I think they must fill their tubes with helium….)
- I like the colour – sort of a gloss Robin’s egg blue which is nicely set off by the Unitron gloss black and bright metal hardware.
- The lens is exquisite.
Early production runs were mistakenly labeled 92mmF7. They were all actually 94mm. This was corrected in later production runs. (mine is labeled 92mmF7)
The only plastic on the scope is the dust cap and the focuser & tube ring knobs.
Basic Specs
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But how does it perform?
The big joke about buying a new scope is that the minute you receive it, the clouds roll in and the heavens open up for at least a week. I sort of have the opposite problem. Gorgeous clear weather for 4 days……..but no mount to put the scope on. So my impressions are formed from looking out my office window with the scope ‘shimmed’ up on books, etc.….(a real poor-mans AZ mount..)
I’ve owned both Televue Rangers and their 60mm APO both of which shared the same focuser arrangement (sliding drawtube with helical focuser w. ¾” travel) which I never really liked. So, I was a bit hesitant about the similar arrangement on the 94mm. The thing that makes the difference is the 2-1/4” travel rack & pinion focuser. It is smooth and precise and because of its travel you don’t have to be accurate on the sliding extension. In practice, you really only have to do it once depending on whether you are using it for astro or terrestrial use. The extension tube slides easily and locks in place and the R&P focuser is smooth and backlash free with lots of focus travel.
Looking out my office window, the usual CA culprits of roof lines or branches against a bright sky show no CA in-focus, with a very subdued red or green on either side of focus. In my books, this is good enough to be called an APO. (Especially back in the day!) I would say it is equal to or better than a Televue Genesis SDF I owned years ago. That’s no mean feat considering the Genesis came along a decade later and used fluorite glass in its optical train.
The in-focus images are ‘hard’. By that I mean they are precise, no mush, no ambiguity. You know you have focus. Images are bright and tight.
I have not yet had the scope outdoors to see how it performs astronomically (no mount), but I will amend this review once I have done that.
In the meantime, I am fascinated by the scope. It is simple, elegant, well made and performs well (in limited testing) – and it has a history, which I always consider important. (will your Uber Chinese APO still be around in 50 years with a story to tell…?)
Hopefully, these observations and opinions will help anyone that is confronted with the pleasant torture of deciding whether to buy one of these scopes.
- Bob Campbell, cahanc, coz and 12 others like this
36 Comments
A classic piece of astronomical history, enjoy. I always tell ppl who are complaining about their 10th cheap n cheerful Chinese scopes to consider spending a little more and get a 'top shelf' scope instead. Don't get me wrong I do have a few chinese scopes and they are good but once you use Takahashi or Astro-Physics, you know the difference. Both optically and mechanically.
I really don't understand the point of the jab at the end about Chinese scopes. Comparing this with anything mass produced is nonsense, because they are build on different manufacturing and design philosophies.
You talk about the APO revolution, I'll argue that the story of the Chinese APO revolution will also be remembered in 50 years.
I've owned two of these, and my most memorable visual image of M42 was through the 94. The background was inky black, contrast incredible, stars pinpoint. They're built like Tele Vues - the proverbial tank. I was not real thrilled with the focuser lock down, though as you say it was before its time and non-marring, and a previous owner had obviously tightened one of the setscrews with a pliers and bent it, as you really had to tighten those screws (a bit painful so I wore work gloves to do it!) to be sure your diagonal didn't fall out. My wife really liked that baby blue color. The guy I sold the first one to put an expensive new focuser on it and was thrilled its performance.
Your first impressions bring back wonderful memories. The little blue Brandon with Christen triplet lens and Unitron hardware was a great scope when it was introduced in the late 1980’s and still shows the same wonderful images of the universe today.
At that time fluorite was already used by Takahashi in their FCT triplets and FC doublets and Vixen used them in their FL fluorite series. These were all very expensive in the day and Brandon along with Astro-Physics made an effort to produce great quality refractors at a somewhat friendlier price. Performance was still not quite up to the level of those Japanese fluorites though. The Brandon was one of the best looking refractors though and very compact. The ads in S&T were legendary. Enjoy your new scope!
I didn't buy this new, but I did get three of them for around $700 each in the 1990s. Smallest scope I've used that showed me six stars in the Trapezium. The first unit was 92mm, the second two were 94mms. Interestingly, I did not get one of the lighter models (some wanted the Unitron focus slimmed down) that came later. People need to remember, back then, there were few rich fields, let alone apo/ED richfields and they cost money, like Apogee's 4 inch achro. One thing I liked was the long drawtube. Today, it might turn people off, but how often have you seen a sliding component in a telescope that long, that had basically no sag? The scope will stand up very well today to current short ED scopes, maybe better as the cemented lens has great contrast.
Nice review - A fusion of Astro-Physics, Unitron, and Brandon, in a wonderful sky-blue color, this is a classic refractor!
A local friend of mine, old ski-bum buddy, recently told me he inherited a telescope from his uncle or grandfather or something, family is from upstate NY....it turned out to be this! Needless to say I was pysched and helped him set it up & use it a few times. Wonderful lens. The original alt-az mount is broken can barely works, I'm trying to get him to buy something like a Vixen Porta or simliar to make it easier to use. the planetary images are excellent so the lens is still working great
Great mini review of a true classic and a nice easy read away from all the tech jargon.
Hi Erik, I stand corrected. It seems like some camera and microscope mfrs and the high end guys (read Takahashi) were utilising fluorite 'glass' before the advent of the Vernonscope 94F7. The issues as I understand it (now) were that at first, flourite was a naturally grown crystal which was limited in size, and thus was utilised in small objectives like microscope lenses. As synthetic flourite crystal was developed, larger sizes became practical (but not cheap as you observed...).
There's no doubt that the Chinese manufactured APO scope have allowed us to afford this next step up from an achromat. I guess the thing that has me fussed about it is that they're all of a piece. Typically the lenses come from a couple of manufacturers and the various brands house them in their own mechanicals. Your Williams Optics APO is likely the same as an Explore Scientific which can also be the same as your Bresser or TS Optics....
What a beautiful scope. For someone like me who hasn't been in astronomy that long it's really cool to see a bit of history like this. Thank you very much for sharing!
That Chinese APO revolution has made it possible for people like myself to enjoy APO image quality. Not everyone can afford a Tak or an AP.
btw I think you mean "flaunt" not "flout"...
Congratulations on acquiring it and sharing your experience. This scope has great optics. I’ve got one set of them in a custom made Moonraker OTA which I use in tandem with a large 10” f/20 Mak for visual work. Lovely wide field views to contrast.
https://cdn.astrobin...x0_2naJ1p0L.jpg
https://cdn.astrobin...x0__OBgH3qw.jpg
Roberto
Yup - I'll correct that when I post an update. I now have the mount made.....no excuses....lol
Goto Optical released the first commercial fluorite telescopes in 1976. Takahashi offered the first modern Apo and Semi-Apo telescopes in 1972 but made with ED elements or Schott flints, not fluorite. As an aside Zeiss offered their B lens Apos in the very late 1800s. MIT started a fluorite growing study group in 1926 IIRC and a process to do so was patented in US in 1949. American telescopes makers were out of the Apo picture until Roland acquired the famed NASA glass (Schott flint) and offered a pair of Apos in 1982. My Roland Brandon 94mm f7 is first year or so and marked 92mm. Wonderful scope.
I believe Roland worked with fluorite for the Stowaway 92mm f/5. Had one of those and it was amazing. Could be wrong but I believe he didn't like it as a lens material to work with.
Your examples aren't accurate, with a little search work you can find out who makes what, and who buys from which supplier to package. Even if you were right, So what? Do you go to a lawn and garden store and bemoan the fact that all the different lawnmowers or chainsaws only use engines from a few companies?
What matters is that many of them are good and put a certain level of performance in a price range that is accessible to more people. Are they all gems? No, but then that is true of any old brand you want to look at. Even Roland has re-figured his own lenses when sent in to be serviced because he has better ways to test now.
You got a classic scope which you are proud of, good for you, glad you're happy with it. But don't use it as an excuse for low-key snobbery.
Over time some William Optics APO refractors had optics by TEC and some by TMB so don't lump them with the Chinese all the time. Many companies like Stellarvue also did that in their early days until they were priced out of the Russian optics market and had to go elsewhere.
The Brandon 94 was in fact, part of the inspiration for Zeiss to create thier 100/640 APQ. I've had a couple of examples of the Brandons, a great richfield scope that was a heck of a lot of fun to use as I would sweep the milky way with a set of Brandon Vernonscope eyepieces. I did not like the focuser as it felt like a plastic toy - note I am not much of a Unitron fan so I didn't appreciate it as others might. Always wanted to view through the 130 version as well - some of the 130's had white tubes.
Don't know about an Uber Chinese APO, but my Astroscan is coming up on 48 years now, and it has its own story to tell!
Nice review. I owned one for a while and it was a great “little” visual scope. Sold it when I picked up an original Stowaway f5.
I still own the Brandon 130 in the same blue. Same build quality as the 94, but has a tad better color correction overall.
Very nice review, i recently purchased one and upgraded the focuser to a feather touch. I tried to clean and adjust the old focuser but i guess modern focusers must have spoiled me. Any insight on what eyepieces compliment this scope? I am looking to upgrade my eyepiece collection to all Tele Vue's . Thanks
Thanks for the review. I've had mine for close to 15 years and love the scope. I think of it as a half sibling to my mid '80s, AP 6" f/8. Sweeping the Milky Way with a wide field eyepiece is wonderful, and it does a surprisingly good job on the planets too. I saw a good amount of detail during a Mars opposition. Like the 6 inch, the Brandon give pinpoint stars and contrasty, sharp views.
I'm fine with the stock focuser because the long drawtube will accommodate anything I want to use, and the rack and pinion won't slip with heavy eyepieces even when the scope is vertical.
I first looked through one at Saturn back when they first hit the market, and was very impressed. I wanted one ever since, and eventually grabbed one. I figure chances are, it may be with me till the end of my hobby when of being too old to set-up larger scopes. I piggyback mine on the back of my 12" SCT, and use it as my portable scope on a iOptron ZEQ25GT which is a perfect match for the Brandon.
Like my 6", I've occasionally considered a replacement with modern glass, but always end up questioning if the improvement would be worth the added expense, and for me, I conclude the answer is no. The color correction might not be perfect, but they are excellent lenses that provide wonderful views, and that's what I want from my equipment. Even after all these years, that little scope still can still impress me. That says something.
As for the question of what eyepieces compliment the scope? They are very eyepiece friendly. I use mine with all kinds of different eyepieces. Of course, being a shorter focal length, you'll obviously need shorter focal length eyepieces if you want high power. You'll definitely want a 2" low power, wide field eyepiece. One thing I've found regarding eyepieces is weight can be an issue. While my larger eyepiece perform wonderfully - i.e. my ES 100s, or my monster 30mm MEade UWA, they really throw off the balance of the scope and mount, so I tend to stick with lighter eyepieces. Because the scope eyepiece friendly, you can get away with 2" eyepieces of simpler designs. One of my favorite is an old 1980s 32mm, 80+ degree, University Optics Widescan. It's almost as sharp as the Meade and way lighter. In the TeleVue line you may find the longer focal length Panoptics, and the 31 Nagler type 5 might be kinda' big and heavy depending on your mount, even though they'd give outstanding views. One of those would be fine if you were going to do primarily wide field scanning and balance accordingly, but not so much if you are doing general observing where you are frequently swapping them out with smaller eyepieces.
Celestron sold a calcium fluorite lensed 4" refractor in the '80s. It was a doublet at f/8.8-f/9:
https://www.cloudyni...rite/?p=1737849
Not exactly a plethora of choices......and I'll bet their cost put them out of reach of most astronomers..