Brand: Sky-Watcher

Sky-Watcher Flextube 250P 10" Collapsible Dobsonian Telescope (S11720)

S11720

Brand: Sky-Watcher

Sky-Watcher Flextube 250P 10" Collapsible Dobsonian Telescope (S11720)

S11720

  • Large 250mm aperture delivers stunning viewing experience
  • Innovative collapsible design that retains collimation
  • 1235x more light-gathering power than the human eye
  • Patented tension control handle allows for precise slewing and maximum stability
  • Parabolic primary mirror with Radiant Aluminum Quartz (RAQ) coating for 94% light reflectivity
  • Heavy-duty rocker box with Teflon bearings provide a stable base with smooth motion
  • 2-inch Crayford-style focuser with 1.25-inch adapter allows for use of nearly any eyepiece
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22% OFF
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Why We Love It Full Details What Can I See? What's in the Box? Specifications Reviews and Questions Articles, Videos, Software, Links

Why we love the Sky-Watcher Flextube 250P 10" Collapsible Dobsonian Telescope (S11720)

Dobsonian telescopes are some of the best beginner telescopes available. They're simple to use, and open the night sky up to everyone. These scopes will give incredible views of the planets, mind blowing views of the moon, and some really interesting views of deep sky objects like galaxies and nebulas. For a bit of context, the human eye is capable of seeing approximately 10k stars on it's own. That number goes up to 50 Million when you use this 10 in dobsonian telescope.  You'll neve outgrow these scopes, they are perfect for visual astronomy.

For decades, the Dobsonian stood as a DIY staple of amateur astronomy, usually constructed with two mirrors, a tube and a base. Often referred to as '˜light buckets', Dobsonians provide users with the highest possible aperture for their money when compared to telescopes of a similar size, such as Schmidt-Cassegrains or refractors.

Product Description

Developed in the 1970s, the Dobsonian-style telescope is an inexpensive solution for bright, detailed visual observing using a simple design. The name '˜Dobsonian' comes from the telescope's inventor, John Dobson, a Vedanta monk who popularized sidewalk astronomy and dedicated his life to astronomy outreach. Dobson was well known for constructing large aperture reflecting telescopes capable of deep sky viewing, using low cost materials. These were often made with found materials, heavy cardboard tubes, recycled porthole glass, and plywood mounts. Dobson, who literally wrote the book on how and why to make amateur telescopes, encouraged other astronomers to assemble their own telescopes and taught workshops on telescope making.

The Flextube Dobsonian innovates on that original design, offering users the ability to collapse the optical tube using a proprietary truss-tube system while retaining its collimation. The optical tube uses a parabolic primary mirror, constructed of borosilicate, then polished and coated with our proprietary Radiant Aluminum Quartz (RAQ), producing a remarkable 94% reflectivity. With a 10-inch aperture, the Flextube 250P Dobsonian collects 1235 times more light than the human eye! This simple yet effective design is perfect for visual observation of faint objects, such as nebulae, star clusters, and galaxies.

Supporting the Flextube Dobsonian is more than just a simple rocker box. The base uses Teflon bearings for smooth, easy Azimuth slewing and a patented tension control handle to lock the telescope in place. Once locked on an object, the telescope can support both 1.25-inch eyepieces as well as the heavier 2-inch eyepieces, allowing you to use virtually any eyepiece on the market. All Flextube Dobsonians come with a slew of accessories, including: two 1.25-inch eyepieces, a 1.25-inch eyepiece adapter, a 2-inch eyepiece adapter, dust caps, and a 8x50 finderscope.

At Sky-Watcher, we stay true to the traditional John Dobson design, while offering a fresh look for the 21st century. Although we love computerized telescopes, using a star chart to find objects by hand can be far more fulfilling and will improve your knowledge of the night sky. Unplug your electronic devices, step outside, and become immersed in the wonders of the universe.

What can I see with a Sky-Watcher Flextube 250P 10" Collapsible Dobsonian Telescope (S11720)?

Here are some simulated views of common objects. Results with your telescope will vary with viewing conditions, obrits, equipment and more.

Jupiter with

25mm Eyepiece - 48x Magnification

(Included with This Telescope)

Jupiter with

10mm Eyepiece - 120x Magnification

(Included with This Telescope)

Jupiter with

5mm Eyepiece - 240x Magnification

Sold Separately

Moon with 25mm Eyepiece

48x Magnification

(Included with This Telescope)

Moon with 10mm Eyepiece

120x Magnification

(Included with This Telescope)

Moon with 5mm Eyepiece

240x Magnification

Sold Separately

Andromeda with 36mm Eyepiece

33x Magnification

Sold Separately

Andromeda with 25mm Eyepiece

48x Magnification

(Included with This Telescope)

Andromeda with 10mm Eyepiece

120x Magnification

(Included with This Telescope)

What's in the Box

  • Optical tube assembly
  • Base
  • 8x50 RACI finderscope

25mm eye piece

10mm eye piece

Specifications

Optical Info
Optical Design Newtonian
Mirror Coatings Radiant Aluminum Quartz (RAQ) coatings with 94% reflectivity
Glass Type Borosilicate
True Aperture (mm) 257
Primary Aperture (mm) 254
F/Ratio 4.7
Focal Length (mm) 1200
Secondary Diameter 64mm
Secondary Obstruction (by diameter) 25%
Secondary Obstruction by Area 6%
Observational Info
Dawes Limit 0.46
Rayleigh Limit 0.55
Limiting Mag. 14.5
Minimum Magnification 36
Maximum Magnification 500
Light Gathering (compared to next size down) 57%
General Info
Focuser 2" Crayford
OTA Length (Retract/Ext.) 31.5"/44"
OTA Outer Diameter 11.375"
OTA Weight (with accessories) 33
Dob Base Weight 26.5
Dob Base Measurements 29.5"x20"
Zenith Eyepiece Height 48"
Accessories
Included Finder 8x50 RACI
Included Diagonal No
Included Eyepieces 25/10 Plossl
Magnification w/ Included Eyepieces 48x/120x
Included Case No
Corrector No

Customer Reviews

Based on 2 reviews
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S
S.L.

I am completely satisfied with my purchase. It was delivered without any issues and assembly was easy.

M
M.H.
Still familiarizing

Have set up everything….i love the charcoal metallic optical tube finish…the collapsing tube also makes the unit much more transportable….really looking forward to my first outing…in the mean time i am researching and learning about my eye pieces and their capabilities and limitations as they are used with the 10” dob…really excited for that inaugural outing!!

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