Product Description
Among Maksutov-Cassegrain telescopes, none is more revered by optical purists than the ultra-premium 7" Questars. Their only drawback is a price that starts at over $9000.
Granted, this 180mm (7") Sky-Watcher Maksutov-Cassegrain is not quite the performance equal of a 7" Questar, but it's in the optical ballpark in side-by-side comparisons at less than 15% of the typical 7" Questar priceQuestar price.
This 180mm (7") aperture Sky-Watcher Maksutov-Cassegrain uses quality Schott optical glass, from the premier German optical glass manufacturer, for exceptional high contrast/high resolution images. Within the solar system you will see lunar features under one mile across; large clouds and dust storms on Mars; as many as six or seven of Saturn's moons; Jupiter's four Galilean moons start to show as tiny discs at high powers; many dimmer asteroids become visible as faint star-like points; and seeing conditions start to limit how much solar system detail you can see on an average night
Outside the solar system, the high resolution 180mm Sky-Watcher Maksutov will split binary stars separated by less than one arc second during very good seeing; some globular clusters will be resolved almost to the core, and there will be much internal detail in nebulas and some visible structure in many galaxies from a dark sky site.
Features of this 180mm Sky-Watcher Maksutov-Cassegrain . . .
Maksutov-Cassegrain optics: 7" (180mm) aperture, 2700mm focal length, f/15 optical system using premium Schott optical glass. The system's Maksutov corrector lens is fully multi-coated on both sides with multiple layers of anti-reflection materials for high light transmission and good contrast.
Internal focuser: Focuses by moving the primary mirror fore and aft in the optical tube by means of a large focusing knob on the rear cell.
Star diagonal: 2" 90° mirror type.
2" eyepiece: The 96x eyepiece is a fully multi-coated three-element Sky-Watcher 28mm LET with a long 20mm eye relief and a twist-up eyecup. The eyepiece field of view is 0.58° across, a little larger than the diameter of the full Moon, for expansive views of the Moon, compact nebulas, and globular star clusters.
Finder: 8 x 50mm straight-through dark crosshair achromatic refractor.
Dovetail: Vixen-style dovetail bar for installing the scope on any altazimuth or equatorial mount using a Vixen-style saddle.
Warranty: two years.
Tech Details
| Aperture | 7" |
|---|---|
| Focal Length | 2700mm |
| Focal Ratio | f/15 |
| Highest Useful Magnification | 338x |
| Weight | 17.2 lbs. |
| Resolution | 0.64 arc seconds |
| Visual Limiting Magnitude | 13.8 |
| Warranty | 2 years |
Reviews
The scope arrived well-packed and in flawless condition. The supplied accessories are not of higher order but are adequate. The 28mm eyepiece is a very simple design (3 elements) but delivers a sharp, attractive image in an f15 scope. Those of us with other maks or experience in long focal length scopes understand how effective simple eyepieces (think kellners) can actually be used with benefit in scopes like these. The included finder is actually fine if you don't need a ra finder. The 2" diagonal was the weakest of the included extras. Poor coatings allowed for stray reflections and noticeable contrast loss. I had several others on hand and confirmed the diagonal to be the source of initial performance concerns. Using another diagonal the contrast levels excelled and I could detect no discernable coma, spherical aberrations, nor astigmatisms with first light. I do not have the expertise to accurately diagnose diffraction rings but can say without reservation, this scope delivers the goods! The first night of testing I was limited by seeing that was about 3.5/5. Nonetheless, I had no difficulty in seeing the pup at 180x and enjoyed tightly focused stars under first magnitude. I mention first magnitude because on another night with seeing at 4/5 those brightest stars also focused tightly. Very close to what you expect in refractors. On that night with 4/5 seeing I was only limited by light gathering power. Jupiter and Saturn both focused tightly with crisp limbs and extensive bandings at 360x. With Jupiter, contrast levels and details within those bands (festoons, inner swirls, etc) were outstanding. The four Galilean satellites all focused into clear, well-defined disk. This is not a particular challenge for any scope of four inches or more providing the optics and mechanics are all well made. Sadly, many common scopes fail such a simple task. Not this one! I mentioned before that the scope was limited only by light gathering power. I was referencing my observations of the moon. With the brightness of the moon on that 4/5 night, I was able to use 540x with complete success and no image degradation. Such magnification is beyond reason in many locations and should not be expected. However, if you live in an area with steady seeing on a semi-regular basis then this scope will not disappoint. The only perceived weakness in my model was the larger than expected amount of image shift. Fortunately, this is easily remedied by installing a thread-on Crayford focuser. Another SW mak may very well have little shift but I was much to pleased by the quality of the optics to even think about asking for an exchange.
In conclusion, I can say from my experience with this OTA, that it's a big performer for a very reasonable price. If you are looking for a planetary scope and splendid double star performer the SW 180mm mak will answer the call for much less money than a high end apo. I would not recommend a large mak as a first scope or even as a choice for anyone inexperienced. Rather I'd suggest this as a compliment to another kind of scope. I have an 11" SCT and a 5" refractor and the 180mm plugs in perfectly, performance wise, to compliment either. This was money very well spent! (Posted on 5/25/2019)
I looked at a couple star clusters and the stars and depth was pretty good.
I was surprised hoe easily the small knob was to focus with. I was super smooth. Going to try with 2" barlow next outing. Also want to try planetary astrophotography some day.
Awesome scope at 2700 mm fl and a great price with the accessories.
(Posted on 10/26/2018)
I highly recommend this product. (Posted on 10/6/2018)
