- 457mm / 18" Dobsonian telescope
- Fused conical primary mirror
- Cellular secondary mirror
- Dual speed 2” Crayford focuser
- Two section truss poles (compact transport)
- Minimalist, all metal construction
- Fast f/4.1 optics for short eyepiece heights
- 18” provides 27% more light than a 16” telescope
- 94% reflectivity coatings
With the introduction of the 18 and 20 inch Stargate truss-tube Dobsonians, Sky-Watcher became the first telescope manufacturer to provide mass-market telescopes with this level of light gathering power. With this kind of aperture you’ll be able to view the most subtle planetary and deep sky phenomenon.
Stargate come complete with three 2.3 pound counterweights, 9×50 finderscope, two eyepieces (28mm, 10mm), collimation eyepiece, stabilizing clamps and ribbed fabric shroud.
Our superior optics just got better
Stargates feature Sky-Watcher’s exclusive fused conical parabolic mirrors. The fused design allows for thinner mirror construction that provides faster cooling and lighter weight.
Combined with the cast cellular secondary mirror and Sky-Watcher’s exclusive 94% reflectivity coatings, Stargate delivers bright, detailed views of your favorite deep sky objects. The 18 inch model captures 27% more light than our 16 inch, while the 20 inch (a full half meter of aperture) boasts a monster 56% more light gathering power.
Solid foundations, easy assembly
The minimalist all-metal structure of the Stargate produces a sturdy and stable platform while maintaining a convenient and compact footprint. The truss-tubes break down to a very manageable 36 inch length for easy transport. Azimuth and altitude bearings are steel and Teflon for smooth, steady movement.
Setting up a Stargate is a simple procedure, taking only about 20 minutes. Spring loaded truss anchor points are clearly labeled to eliminate any frustration or confusion. Adjustable feet make leveling a snap.
Specifications
| Optical Design |
Dobsonian |
|---|---|
| Primary Aperture (mm) |
457mm (18”) |
| Secondary Diameter (mm) |
120mm minor axis |
| Secondary Obstruction by Area |
7% |
| Mirror Coatings |
94% Aluminum |
| Glass Type |
Borosilicate |
| Focal Length (mm) |
1900mm |
| Focal Ratio |
4.1 |
| Light Gathering (compared to next size down) |
Captures 27% more light than a 16” telescope |
| Zenith Eyepiece Height |
74.5” |
| Rayleigh Limit |
0.31 |
| Dawes Limit |
0.25 |
| Limiting Magnitude |
15.9 |
| Minimum Magnification |
65x |
| Maximum Magnification |
902x |
| GoTo |
No |
| Focuser |
2″ Dual Speed Crayford |
| Included Eyepieces |
28mm LET eyepiece and 10mm eyepiece |
| Included Finder |
9×50 |
| Other Included Items |
2.3lbs counter weights (3), Shroud, Truss clamps |
| Upper Cage Weight |
11lbs. |
| Truss Pole Weight |
2.6lbs each. 16lbs total |
| Mirror Box Weight |
62lbs. |
| Dobsonian Base Weight |
40lbs. |
| Fully Assembled Weight (with weights) |
129lbs. |