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Sky-Watcher Flextube 250 Dobsonian 10-inch Collapsible Large Aperture Telescope – Portable, Easy to Use, Perfect for Beginners, White/Black (S11720)

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Availability: Only 8 left in stock, order soon!
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Arrives Sep 11 – Sep 15
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Style: 10" Collapsible Dobsonian


Features

  • LARGE APERTURE: Get a bright, bold viewing experience at a fraction of the cost of other optical designs.
  • INNOVATIVE COLLAPSIBLE DESIGN: Unique strut design allows for optical tube to collapse for ease of portability while keeping collimation
  • PROPRIETARY TENSION CONTROL HANDLES: These patented handles allow for accurate movement without the need for perfect balance.
  • 94% REFLECTIVE MIRRORS: Fully multi-coated borosilicate primary and secondary mirrors deliver exceptional views.
  • TEFLON BEARINGS: Proprietary Teflon bearings ensure smooth azimuth movement.
  • COMES COMPLETE: All accessories such as, 2-inch Crayford-style focuser with 1 1/4-inch adapter, two super wide-angle eyepieces (25mm and 10mm), and 8x50 right-angle finder scope are included with purchase.
  • STURDY AND LIGHTWEIGHT DESIGN: When fully assembled, the Dobsonian weighs only 40 pounds fully assembled

Description

For years, Dobsonian telescopes have provided astronomers with the most bang for their buck using a large aperture and simple design. Viewing with a large aperture can provide a stellar experience, however the size of large reflector telescopes can pose problems for users looking to either store or transport their telescope from one location to another. The Sky-Watcher Collapsible Dobsonian solves this problem with a unique collapsible design using three retractable steel struts, allowing for easy storage and transit. Transport Anywhere, Anytime Dobsonians are known for giving users a large aperture reflecting telescope at a low price, however they often lack portability. Sky- Watcher has innovated this classic telescope design by integrating a collapsible tube system, addressing users’ portability concerns. Sky-Watcher Collapsible Dobsonians feature a strut system carefully designed to ease setup time in the field while delivering consistent optical performance. Each strut has preset indentations which place the optics in the same position time after time, maintaining collimation. Unlike Dobsonians using a truss-tube system, Sky-Watcher’s Collapsible Dobsonian does not need to be disassembled. The strut system is comprised of three 1” steel poles, joining the bottom and top portion of the optical tube. When extended, three chrome locking screws hold the instrument in place. Unlike truss tube Dobsonians, Sky-Watcher’s Collapsible Dobsonian holds collimation extremely well, forgoing the need to collimate each time it’s used. The retracting design can shorten the optical tube up to 36%, making storage and transit much easier. Borosilicate? Gesundheit! At the heart of any Sky-Watcher telescope are observatory-grade optical components. The Collapsible Dobsonian is no exception, using components that yield exceptional contrast, 94% reflectivity and minimal vignetting. Mirrors are constructed with borosilicate glass, then coated with quartz, titanium and silicon dioxide to ensure an unparalleled viewing experience. Combining these superb optics with a large Dobsonian aperture helps ensure you’ll have bright, bold views of faint deep sky objects. To ensure Sky-Watcher Dobsonians remain easy to use, all Collapsible Dobsonians include a mount base that is so smooth, it can be rotated with the push of a finger. 8” and 10” models come complete with Teflon bearings, while the larger 12”, 14” and 16” models use steel needle bearings to ensure smooth and easy movement. Upgraded Pro Models Sky-Watcher’s 14” and 16” Collapsible Dobsonian Pro models offer a few additional upgrades. Pro models also use a conical parabolic mirror to help reduce the weight of the primary and for faster cool- down time. Additionally, a 10:1 dual-speed Crayford-style focuser offers users a more precise method for focusing and needle bearings produce smoother, quieter movement. Pro models also include Sky-Watcher’s premiere collapsible mount which uses an easy-breakdown base for enhanced portability. Normally, these larger aperture scopes would be extremely difficult to transport but with Sky-Watcher’s innovative design these telescopes can be used anywhere. Accessories and More At Sky-Watcher, we want you to feel confident in your purchase, knowing that your telescope will come with all required accessories to start using your telescope. All Sky-Watcher Dobsonian telescopes include a 2” Crayford focuser and a 1.25” adapter, allowing you to utilize both 2” and 1.25” eyepieces. Also included, are two 1.25” eyepieces (25mm and 10mm), a 8x50 finderscope and eyepiece tray.

Brand: Sky-Watcher


Optical Tube Length: 41 Inches


Eye Piece Lens Description: Plossl


Objective Lens Diameter: 254 Millimeters


Telescope Mount Description: Altazimuth Mount


Product Dimensions: 29.5"D x 20"W x 38"H


Focus Type: Manual Focus


Power Source: Adapter


Finderscope: Reflex


Item Weight: 42 Pounds


Product Dimensions: 29.5 x 20 x 38 inches


Item Weight: 42 pounds


Item model number: S11720


Is Discontinued By Manufacturer: No


Date First Available: July 20, 2010


Manufacturer: Sky-Watcher


Country of Origin: China


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sep 11 – Sep 15

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • I think anyone getting this scope would do well and get the Bob knobs for it ,
Style: 10" Collapsible Dobsonian
Well to start off with the scope took no time at all coming from the West coast to the east coast, I was impressed to say the least. I opened the box very carefully because of other reviews claiming easy to damage the Focuser, I didn’t have that problem .the stand went together Very easily meaning I didn’t have to fight any of the pre drilled holes from miss alignment, that was a big concern , so what ever fixtures shy watcher used to drill the pre holes were perfect, I thank you for that , I’m an aircraft builder so I know ,as far as the scope it set right in and the locking handles fit perfectly again well done with there hole matching up, now the test, well 3 night of centrails and rain didn’t happen . Then the night sky was perfect, thank you lord, only hard part was 8* temp , brrrrrr, we fought it out . Orion was out just to the south just clearing all the trees and I went straight to the nebula, oh my what a sight to see , using a 25 mm lens im telling ya the nebula seemed as big as a dinner plate. Sorry to say we couldn’t hang because of the cold , the next night I took it out again and the temp was about 26* , way better then the windy night before, got to show a few other family members and they were blown away as well, now you probably wondering about the mirror Allignment out of the box , the secondary mirror was just outside the donut and the main was just a tad off from falling in the center hole of my lazar collimating , adjusting both mirrors took no time at all, I did order bob knobs for it to make it easier not because of the Allen head screws , but because my losing the included wrench that came with it , dropping it in the grass or even worse down on the prim mirror can’t be good for anyone , can’t wait for the spring to see how I can catch the moon and planets , I’m sure as I could be it will be an awe inspiring sight , yer haw , can’t wait , I have 3 other scopes as well , a mead ETX 90, that is sweet for a small scope . Had that one I think over 20 years now , the other two are a 700x70 refractor from National Geographic, can’t believe for the $49.00 I paid for it , it works great as far as the images, tripod not to good but works , sams club special, looking at the moon is good with this one , haven’t had the chance to observe the wanderers yet the other scope is a inexpensive Bushnell reflector 700x76, looking at Orion the night we used this new 10” sky watcher was pretty good for such a small 76 mm primary mirror, still a keeper ,sorry for a long review , just wanted to make sure you New I was for real, well I hope so anyways, ... show more
Reviewed in the United States on January 17, 2018 by fred houseal fred houseal

  • Telescope missing and parts shattered
Style: 8" Collapsible Dobsonian
We receive two boxes with two bases, no telescope on the delivery. Also the two bases were broken and shattered as seen in the picture.
Reviewed in the United States on April 8, 2025 by Alejandro Alejandro

  • Great Dob scope for star hopping
Style: 8" Collapsible Dobsonian
I purchased this after getting a cheap scope with an unstable tripod. Reading the reviews the Dobsonian mounts were easy to use and great for the backyard. The telescope arrived in two boxes like described and I had already watched YouTube videos on assembling. It really was easy and anyone who has assembled furniture can figure it out. The telescope was also updated based on some of the feedback from other customers. Mine came with a 90 degree finder scope. The main OTA can accept both 1.25” and 2” lenses. The altitude movement was very smooth, however the azimuth movement was sticky. There is a modification for the scope where you install a 12” lazy Susan bearing between the two circular base pieces and I highly recommend it. The lazy Susan will make the azimuth adjustments very smooth and easy. I also removed the 3 feet that came with the telescope and replaced them with 4 x 2.5” locking casters making it much easier to move the scope to the backyard. The scope is a star hopper so you need a basic understanding of the night sky. I took an Astronomy class almost three decades ago. That and a sky application for the phone helped me pick out Jupiter and Saturn. Even in the suburbs with a light pollution of 5 I am able to see the two gas giants easily. You don’t have to wait for astronomical twilight to fade before taking in Jupiter. Once I got my bearings I went for my first nebula and found the Lagoon. It was really a matter of practice with this scope and hopping. If you are looking for a scope to find stuff for you then go for the go to version. The lenses are ok for beginning with. They are both 1.25” but the kit lacks a Barlow. I borrowed the 2x Barlow from the cheap kit, but you can really tell the difference in lenses quality. A zoom lens would also be a good addition to someone buying this kit. I got the laser collimator and moon filter offered by Amazon as a package. The collimator is necessary and I recommend watching a video on how to align your mirrors. I have not found use of the moon filter yet. Here I would recommend a good quality Barlow or Zoom lens. I also wished Amazon carried a light shield for the open truss. You can find one from another reseller and for the backyard with lots of stray light, I’d recommend one. The last thing I’d recommend is a good set of star charts and Left turn at Orion to help you search the night sky. ... show more
Reviewed in the United States on October 24, 2019 by Kenneth S. Goodpaster

  • Nice scope for the cost
Style: 8" Collapsible Dobsonian
I ordered this scope yesterday, and it was delivered today (go Amazon!, I initially ordered though Celestron, but they lied about having it in stock and also charge more). The packaging was sufficient, no damage to the scope or parts. Assembly was easy and tools are included. Took about 20 minutes to put together. Unlike the picture, the mount was black (which I prefer anyway). The collimation was off a little, but better than I expected - I used a laser collimator to get things aligned to my liking. First light was tonight! M42 and Jupiter looked great. I used low power (30x) and high (250x), and both provided reasonable images. Unfortunately the moon was quite bright and it was windy and cold, so the session was short. So far, I'm impressed with the amount of scope I have for the price. I'll update again as I have the chance to do more observing. - Update on 4/14/2013: Viewing has been good. After a bit more collimation, the scope is performing well and I have no complaints. Except with Celestron - they seem to ignore their customers feedback and have not responded by any of my complaints about their service. I am quite hesitant to purchase any Celestron products in the future based on this. ... show more
Reviewed in the United States on February 21, 2013 by LuckyJ

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