As seen in Astronomy Technology Today
By Erik Wilcox
When ATT asked me to review the new Stellarvue 80ED Nighthawk Next Generation and M1 Deluxe Alt-Az mount, I eagerly accepted.
Aside from some quick looks through the very popular SV 80/90s at several star parties, my experience with Stellarvue telescopes was limited to one older Nighthawk. A few years back, I'd gotten to use and compare that particular telescope extensively with several other designs and came away with very positive impressions. The only areas where I thought improvement might be in order were with the rack-and-pinion focuser with which that older generation Nighthawk was equipped, finding it a bit more stiff than I prefer, and the weight of that telescope. However, its weight was a result of the fact that it was simply built like a tank, so that's not necessarily a bad thing. What I remember most though is that it had great optics and from the Nighthawk owners I've talked over the years, I've gathered a strong sense of intense brand loyalty. So I was very curious to see what type of travel scope Stellarvue would come up with.
The Nighthawk NG and M1 Alt-Az Mount were delivered just in time for a week long trip to dark skies of our cabin site on the Big Island of Hawaii. Everything was very well packaged for shipping and arrived in perfect condition. I must say that I wasn't expecting such a beautiful scope! This premium f/7 refractor has a build quality that competes with many of the highest-end refractors I've had the pleasure of using and the Stardust white finish of the optical tube really showcases its overall looks.
The rotating, dual-speed Crayford focuser is just gorgeous, with a buttery smooth action that holds its position under the heaviest eyepieces. A micrometer scale on the drawtube is also a nice, useful touch. The sliding dew shield moves back and forth with a silky ease, yet stays firmly in the fully retracted or extended positions, and the lens cap is metal, with a felt insert. A heavy duty CNC machined clamshell ring holds and balances the optical tube nicely. It has a Vixen style dovetail with a safety catch
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and a bracket for the included red dot finder.
Admiring the collimatable objective lens at an angle, I could see a pretty green-hued multi-coating. The lenses appeared to almost disappear when viewed from straight on, so it seemed as though the coatings were clearly doing the job. Peering into the OTA, I could see no stray reflections or shiny objects - just a jet black tube with two baffles to further eliminate the possibility of any contrast robbing glare. Attention to detail is obvious everywhere and the focus knobs have a nice knurled grip and chrome trim gives them a classy look. The gear reduction knob is easily gripped and has a very smooth feel. Even the compression ring screw on the drawtube is chrome.
The Nighthawk NG delivered to me was also binoviewer-ready, with a removable tube section that allows the telescope/binoviewer combination to reach focus without the addition of a Barlow of OCS as required by most fixed tube telescopes. Unfortunately, because I don't own a binoviewer, I wasn't able to test the scope in that configuration.
The Nighthawk NG arrived with a sturdy airline-portable carrying case with the Stellarvue logo embroidered on the front. Inside, there are several pre-cut holes for eyepieces and other accessories. I carried this case onto the airplane and, in addition to the telescope and a number of accessories, had room for a few personal items and reading material (the latest issue of ATT, of course!) for the five hour flight. The zippered case has a convenient handle, as well as an adjustable shoulder strap.
The M1 Deluxe Alt-Az Mount is of a very unique and innovative design. With the exception of its stabilizing section/extension bar, the mount is very light in weight. Despite the lightweight design, it proved to be a very sturdy mount. The tripod legs have three sections that, when fully extended, place the eyepiece height at nearly 6-feet (with the scope pointed at a 45-degree angle). Even with all three legs extended, stability wasn't noticeably affected. The stabilizing section directly under the scope's center of gravity really does its job very well. The tripod leg sections collapse inside of each other to about 18 inches long and the stabilizing bar is easily removable (without tools) for transport, making for a very compact package. Large, knurled aluminum knobs adjust the motion tension in each axis and they work flawlessly. Motion in both axes was smooth, predictable and sure. The M1 Deluxe Alt-Az Mount that I tested included an optional handle that made slewing the scope even more convenient.
Conditions couldn't have been better for the scope's first light. It was a moon less night and the skies at my cabin site are pristine, with no lights nearby. The site is on the slopes of Mauna Loa, at an elevation of 4,500 feet, and the limiting magnitude approximately 7 on most nights. M51 is naked eye visible when high enough in the sky (the site is at 19 degrees North Latitude) and despite a bit of VOG (volcano fog) along the horizon from the very active Kilauea volcano, transparency was excellent overhead. On this night, M36 and M37 were naked eye, so I started with them. At 23x, both clusters looked like tiny diamonds scattered against the jet black sky, and fainter M38 was very nice as well. Over in Orion, an unfiltered view of M42 showed extensive nebulosity and the four main components of the Trapezium were easily resolved. At high power, the "E" component was visible with averted vision and installing a Thousand Oaks narrowband filter gave the nebulosity an intricate, textured look. At 187x, Saturn showed a plethora of detail, with the planet's disk glowing through the translucent Crepe Ring. Despite the low tilt of the rings, the Cassini Division was visible with little effort and banding detail was quite evident on the disk - nice performance for a 3-inch scope!
A star and Ronchi test showed very good optics and chromatic aberration was only visible on the brightest stars, like Sirius. Stars really "snapped" to focus at any power. Even at high magnification, the mount was solid, with less than three seconds of dampening time needed after a solid rap on the side of the legs. For the next several nights, I had a great time with the Nighthawk NG and Mount, and the hours seemed to pass by much too quickly. Often, I found myself just scanning the Milky Way at low power to admire the star-fields, which were tight and crisp from edge to edge.
Back in California, I got the scope out on several nights (under much poorer skies, of course) and by this time, the moon was waxing towards the first quarter. In focus, there was very little chromatic aberration visible at any magnification; a bit of a pale magenta along the limb if I really looked for it, but certainly nothing to complain about. I saw very little violet false color on the moon, despite its minor presence on the brightest stars. Unlike many of the medium focal ratio achromats I've used, I
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[I] never felt that the very small amount of chromatic aberration in this scope detracted from the views. The moon's deepest craters and shadows were virtually colorless and the views were simply beautiful. A low-power view showcased the moon's earthshine and its beautiful contrast against the background sky. I'm generally not much of a lunar observer, but I'm continuously amazed at how much detail one can see with even a small scope. The Nighthawk Next Generation did not disappoint!
I always find it important to mention the positives as well as any negatives in my reviews. I want the readers to get an accurate overall impression of how a product performs, as well as its specific attributes and its potential downsides. But, with this review, I must confess that I'm struggling to come up with anything remotely negative. The build quality and functional aspects of the Stellarvue 80ED Nighthawk Next Generation telescope would be very difficult to improve upon. The optics are excellent and though the color correction isn't quite "apochromatic" it's far better than that of a standard achromat. On all but the brightest objects, I was hard-pressed to see any false color; the exotic ED lens element really does the job. The focuser is extremely smooth and precise and with a slight tension adjustment, it had no problem holding my heaviest 2inch eyepieces.
And the mount is simply the best travel option I've seen, period. The stability is much more than I expected and I love the ability to place the eyepiece height at nearly 6 feet high (I'm a tall guy). The optional 2-inch Stellarvue mirror diagonal with which the telescope was supplied is also very good, with a build quality that complements this excellent telescope. It's often been said that there is no "perfect" telescope, as each design has its compromises and limitations. That may be true, but if the parameters are a beautifully designed and well built 80mm scope with great optics, on a stable, yet portable mount, it would be tough to beat the Stellarvue 80 ED Nighthawk Next Generation/M1 Deluxe Alt-Az Mount combination.
Whether you're considering a telescope/mount for travel or for simply setting up in your backyard, you'll be hard pressed to find a better combination of functional optical excellence and convenient, stable mounting. Having experienced its latest version, I'm confident that the already huge popularity of the Stellarvue Nighthawk series is about to increase even more.
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