Is an 80mm, richest field refractor really the Goldilocks scope? Not too large, not too small – just right! If my four hours of observing last night is any indicator, the answer is “yes!”
I’ve owned two smaller scopes I thought were terrific – an Astro-tech 66 and a 60mm Televue. I really didn’t like parting with either, but priorities change and while I got some good milage out of them, I didn’t use them that often. Why?
Certainly not for lack of portability because they are as portable as it gets. And the quality on both were stunning. And they always delivered more than I expected. But, in the end for me using them was more a stunt – more an attempt to prove to myself how much I could do with how little. For someone else – especially someone who travels frequently – the portability may turn these two scopes into something much more practical than a stunt. But I rarely travel beyond my neighbor’s yard. My idea of portability is being able to move 10-feet to avoid a tree that’s blocking my view. And I don’t really need the quick-look capability of “grab and go” when the scope in my observatory can be operational in two minutes flat and the 15-inch in less than five minutes.
So when I say portable what I really mean is my aging muscles should be ab;e to easily pick up the scope and tripod and move them 30-feet without any heavy breathing. In fact, I should be able to carry the scope, tripod, eyepieces, and my folding observing seat all on one trip. With the 80mm on a Voyager mount that’s possible – though I admit, it was certainly easier with the 60mm sitting on its Bogen tripod. OK, maybe it would be more sensible to make two trips sometimes
But what I’m buying on the used market may fill that bill – along with what I have on hand now and what I learned from using a similar-sized scope last night.
Let’s start with the new – to me -scope. It’s known as a SV80S Stellarvue. It’s apochromatic triplet object was made by Lomo, a Russian firm, and is legendary within the circle of small refractor fanatics. (I’m an apprentice member of that circle.) Here are the highlights from Stellarvue’s Web site where they still offer a limited number of these for $1,795 new. (What I ssume is the Chinese version – probably as good – sells for $600 less. I’m getting one that’s four years old and uses the Lomo objective and I’m paying $1,000 – far more than I ever thought I would dream of paying for an 80mm scope. Oh – those highlights are:
- 80mm f-6 480 mm apochromatic triplet
- Fully multicoated objective for both visual and ccd use
- Stellarvue’s exclusive easy one touch cnc clamshell mounting ring with Vixen rail
- Genuine Feather Touch 2″ dual speed focuser with compression ring 1.25″ adapter.
- Retracting dew shield
- Instrument White high temperature powder-coating
- C7 side reinforced airline carry on case included (shown with optional accessories)
- Each one is triple tested including a star test by Vic Maris
Oh – it’s about 16-inches long and 7-8 pounds with diagonal and finder – though I’m not at all sure I’ll use a finder on it. More on on that later.
Sounds great. And while mine will come with the original – smaller – case, I can purchase the cae pictured here for it and that is a key to portability because of the great selection of eyepieces and accessories you can include. So I’ll invest another $70 and get this case just to nake the whole observing set-up more portable.
But is it really necessary to go to this extreme quality? honestly, I have my doubts. I mean I know color will not be an issue with this scope and the two-speed focuser is very helpful with any scope this fast where focus is more critical than with slow scopes. But will this outperform a Short Tube 80, the uniquitous little Orion that can do wonders and can be bought used for one tenth the price? Yes – absolutely. But how about a higher grade scope like Celestron’s Onyx 80? I have one, was planning to sell it, and that’s what I was using last night. The Onyx is one slick little scope and its optical performance is very nice. I’m going to hold on to it long enough so I can do some side-by-side testing. I hope the Stellarvue will have the edge, but at more than three times the cost of the Onyx it should. Yes, as you pay more the cost per unit of improvement goes up – I don’t expect to see anything but a slight improvement – but I hope I’ll see that. And there’s something more involved – the scope has a sprt of history/personality but around its Lomo lens. And there’s ac ertain satisfaction inknowing that you are using the best,therefore if you are failing to see something you expect to see, theproblem is either you or atmospheric conditions. You’ve pretty much eliminated your equipment as a potential source of problem.
I decided to use the Onyx last night because it was handy and because I wanted to see just how much I could expect from an 80mm scope, since I’ve been using either 60, 100, or 120mm lately. Here’s Celstron’s talking points on the slick little Onyx (no longer in production):
Onyx 80EDF – General Features
- Premium 80 mm refractor
- Celestron’s Starbright XLT high transmission coatings
- Celestron combines a Fluorite based, low dispersion glass with high density crown glass for virtually color-free images across the visible spectrum
- 2″ Crayford style focuser minimizes image shift
- Rotatable focuser for easy framing of objects for photography
- Extendable lens shade reduces glare and protects lens from moisture
- Built-in sighting scope to help accurately locate objects
- Integrated dovetail compatible with Celestron Computerized “GoTo”
- Aluminum case for convenient storage and protection
The one worth siglling out here is this one:
- Built-in sighting scope to help accurately locate objects
This is a big mistake. It;s not a “sighting scope” at all – just apeep hole and as far as I can tell it does no good at all. However, it is removable (one screw) and I’ve put a Rigel finder on there in its place. I also mounted a laser there. But I didn’t have either of these on it last night. Instead I simply used a 24mm Panoptic. (A 24mm Hyperion or 32mm Plossl would give the same field.) The result is a true field of view of about 3.2 degrees which is typical of the field for large astronomy binoculars. In fact many give even smaller fields. I found the combination of the large field, plus 80mm of light-gathering power in the objective , makes it very easy to find everything from planets and bright stars, to very faint, low-surface brightness deep sky objects like M33. What’s more, once you find them it’s a simple matter to boost the power. (I had tried a bargain-priced, 30mm eyepiece with an 82 degree apparent field of view. Works fine and delivers almost five degrees true field. But I find it a bother going from this eyepiece – which is a 2-inch- to higher-powered 1.25 inch eyepieces. Hmmm. . . if I were using all Hyperions that wouldn’t be an issue. Anyway – little stuff like that can put me off sometimes. I don’t like fumbling with small parts and set screws in the dark anymore than I have to. )
But this is “richest field” aspect is really one of the most impressive things about using an 80mm scope with a short focal ratio thus making the scope its own finder. I found deep sky objects in particular easier to track down with this scope than with the typical finder, whether it be a Rigel, red dot, or 8×50 optical finder. The key, of course, is the light grasp. Another key is being able to sit comfortably behind the scope, as opposed to using a Dob where you sit at the side. Sitting behind this scope I found I very quickly developed a pretty accurate sense of where it was pointing – a sort of shoot-from-the hip type of thing. I don’t know how to teach it or even explain it, but it just feels natural. Look at where your target is and while looking, point the scope. I think your eye-brain work to deliver a solution if you get out of the way! If your off a little, start a systematic sweep and you should soon pick up your target – assuming, of course, you have some idea what your target should look like!
I reported on my eveniong targets earlier in this post. The most astonishing thing there for me was a very clean split of the triple, Iota Cassiopeia – not bad for an 80mm! This morning my frist targets with the same set up included M42, M50, the Christmas Tree Cluster, M1, plus M35. With M35 I could also see NGC 2158, which looked a tad like M1, only smaller, though of course they are much different objects. NGC 2158 is really a star cluster much more distant than M35. Seen together the two open clusters provide a wonderful sense of depth of field.
Castor, an easy triple star, split at 72X and was much better at 100X. I also looked at Saturn, rising in the east below Leo, and was able to see Titan and one other moon. The Leo Triplet of galaxies, M65, M66 and NGC3628, was so simple to sweep up! I just pointed the shope at Chertan, one of the stars in the triangle that marks Leo’s haunches, then slowly swept south and a tad east. Bingo – it took about 15 seconds I think. A more challenging pair were the galaxies M81 and M82. But I just remembered that, as I think Sue French once wrote, “the Great Bear has ear mites.” So I pointed the scope in the direction of his ears and prowled around. Took longer this time, but boy do these two pop in this little scope at that power. What’s more, crank up the pwoer a bit and you can easily see that M81 is a spiral and M82 is a “cigar” with dark diagonal cloud cutting through it.
So why am I seeing the short-focal length 80mm as the Godilocks of scopes? To summarize:
1. Portability.
2. At low power you don’t need a finder because the field is both wide and bright, a great combination.
3. While it should be obvious that larger scopes will reveal more, you can get the essential astronomy experience – the feel for a galaxy, nebula, or star cluster – with an 80mm – certainly exhaust the Messier catalog and much more, as well as split many of the best double stars and do casual viewing of planets and Moon.
And one last point on the portability front – it is short enough so that a reasonable size and weight tripod and mount, such as you have with the Astro Tech Voyager, will work. Longer scopes on this mount can put you awfully close to the ground when you’re trying to look up. With the 80mm there are no acrobatics – and no acrobatics trying to orient your eye to a finder either, since you aren’t using one!











