Sky-Watcher Stargate 18" f/4.2 Truss-Tube GoTo Dobsonian Telescope

Sky-Watcher Stargate 18" f/4.2 Truss-Tube GoTo Dobsonian Telescope

Sky-Watcher Stargate 18" f/4.2 Truss-Tube GoTo Dobsonian Telescope


Now Viewing:

Special Order
Expected availability: 7-14 business days

Product Highlights

  • Large 18" (457mm) Aperture
  • 1900mm Focal Length, f/4.2 Focal Ratio
  • 42,900-Object SynScan GoTo Controller
  • Multiple Alignment Procedures
  • PEC, Backlash Compensation, PAE
  • 2" Two-Speed Crayford-Style Focuser
  • Floor-Standing Motorized Alt-Az Mount
  • 10mm, 28mm, Collimation Eyepieces
  • Large 9x50 Finder with Bracket
  • Easy-to-Manage Open Truss-Tube Design
Show moreShow less

Aperture: 18" f/4.2

18" f/4.2 20" f/3.9

Not available with current selections

Stargate 20" f/3.9 wzawrtsdcueqwrebbq

Special Order

Mount: GoTo Alt-Az

Manual Alt-Az

Special Order

GoTo Alt-Az

B&H $500 Gift Card Dash

Share for a chance to win a $500 B&H Gift Card!

Share on Twitter

Share a favorite product for chances to win one of eight $500 B&H Gift Cards!
1 new winner announced every Monday starting Nov 5th!
Limit 1 entry per day: Come back every day to increase your chance of winning.

Be sure to mention #BHWishList when you share!

Congrats to our winners so far:

Next winner: Nov 19th

James Z. (Wk 1)

Ralph H. (Wk 2)

Official Rules


NO PURCHASE IS NECESSARY TO ENTER OR WIN. The B&H $500.00 Gift Card Dash (the "Sweepstakes") is void where prohibited by law and is sponsored by B&H Foto & Electronics Corp., 440 Ninth Avenue, New York, NY 10001 ("Sponsor"). It is not sponsored or endorsed by Facebook or Twitter in any way.

Entry Period/Methods of Entry. The Sweepstakes will run from on or about October 28, 2018 until on or about December 23, 2018 (the "Entry Period"). Entries received outside the Entry Period are void. Enter the Sweepstakes via either one of the following methods. (1) Share any product found on the B&H website (the "Website") on Facebook or Twitter via the dedicated links contained on the website using the hashtag #BHWishlist; or (2) Mail a postcard (postmarked during the Entry Period) containing your name, address, phone number, and email address, and indicate the subject(s), if any, about which you are interested in receiving future emails from B&H (e.g. photo, video, audio, computers, home theater, portable entertainment ) (optional) to: B&H $500.00 Gift Card Dash Sweepstakes, c/o B&H Foto & Electronics Corp., 440 Ninth Avenue, New York, NY 10001 (either option, an "Entry"). Entries must not, in the sole and absolute discretion of the Sponsor, contain obscene, provocative, defamatory, sexually explicit, or otherwise objectionable or inappropriate content. Entries deemed by Sponsor to be inappropriate will be disqualified. Entries owned by a third party, or the use of any trademarks, service marks, logos, brands, or products owned by a third party are not acceptable for entry into the Sweepstakes. Limit 1 entry per person, per day.

Winner Selection/Prizes/Odds. The B&H Social Team will randomly select a winner from among all eligible entries every Monday during the Entry Period, for a total eight (8) winners (each a "Winner"). Each Winner will receive a B&H Gift Card pre-valued in the amount of $500.00. No cash or other substitutions will be offered. Winner selection is in the sole and absolute discretion of the B&H Social Team. Any taxes are the sole responsibility of the winner. Winners will be notified and receive their prize at the email address associated with the account to which their Entry was posted or the email account provided with a mail-in entry. The odds of winning depend on the number of eligible entries received.

Identity of Winners/Eligible Participants. Winners will be identified by the email account associated with the Facebook or Twitter account from which their Entry was submitted or the email account provided with a mail-in entry. An email account holder shall mean the natural person assigned to such email account by the internet access or online service provider or other organization responsible for assigning email addresses for the domain associated with such email account. Any issues regarding the identity of a Winner shall be resolved by Sponsor in its sole discretion. The Sweepstakes is only open to residents of the United States that are at least eighteen (18) years of age on their entry date and is not open to employees of Sponsor, their immediate family, any person domiciled with such employees, or any affiliates or subsidiaries of Sponsor.

Entry Ownership/Entrant Agreements. Entrants retain full ownership and copyrights to their Submission. However, by entering the Sweepstakes entrants grant Sponsor permission to use their Entries for promotional purposes on their respective social media channels with proper credit. Entrants also agree: (a) to be bound by these Official B&H $500.00 Gift Card Dash Sweepstakes Rules; (b) that any claims related to this Sweepstakes shall be resolved individually without resort to any form of class action and that awards, shall be limited to actual out-of-pocket costs incurred in entering the Sweepstakes, and shall not include incidental or consequential damages or attorneys fees; and (c) that any actual or perceived ambiguities in these rules shall be interpreted by Sponsor in their sole discretion.

Limitation of Liability/Sponsor Modification/Cancellation Rights/ Choice of Law/ Venue/ Winners List. Sponsor is not responsible for incomplete entries or for failure to receive entries due to technical failures or human error of any kind. Winners agree that Sponsor will have no responsibility for losses or damage of any kind resulting from the acceptance, possession, or use of the prizes. Except where prohibited, participation in the Sweepstakes constitutes entrant's consent to the publication of his or her name by Sponsor in any media for commercial or promotional purposes without limitation or further compensation subject to Sponsor's respective Privacy Policies. Sponsor may modify or discontinue the Sweepstakes at any time and may disqualify from the Sweepstakes any person it determines, in its sole discretion, to have attempted to or actually tampered with or otherwise abused any aspect of the Sweepstakes. Entrants agree that in the unlikely event a dispute arises in connection with this Sweepstakes, it will be governed by the laws of the State of New York and heard exclusively in a court of applicable jurisdiction in the County and State of New York irrespective of any choice of law provisions to the contrary. To receive names of the winners by U.S. mail, please mail a self-addressed stamped envelope to: B&H Foto & Electronics Corp., Attn: B&H $500.00 Gift Card Dash Sweepstakes, 440 Ninth Avenue, New York, NY 10001. Any Winners List request must be received by B&H within one (1) year of the date the Sweepstakes is conducted.

Let us know how to reach you if you win!

Privacy 100% guaranteed; email address for contact purposes only


Already have a B&H account? Just log in tomorrow to enter again!

Price: $6,999.00

Instant Savings: $500.00

$0 VA Sales Tax Collected on This Item
Add to Wish List Item in Wish List

Sky-Watcher Stargate overview

  • 1Description

With the extremely large light bucket users have come to expect from a Dob and the added convenience of a fully motorized GoTo mount, the Sky-Watcher Stargate 18" f/4.2 Truss-Tube GoTo Dobsonian Telescope gives users exceptional performance with a low dollar-to-aperture cost. Proprietary aluminum mirror coatings ensure maximum reflectivity, and a fused conical parabolic primary mirror design allows for thinner mirror construction. This provides faster cooling and lighter weight while also correcting spherical aberration to eliminate distortion across the entire field of view, especially at the edges.

This telescope's large 18" aperture draws in a tremendous amount of light to reveal awe-inspiring details of the Moon and planets. Deep-sky objects will be visible even for inexperienced observers and bright star clusters can be resolved to their core. Its f/4.2 focal ratio and dual-speed Crayford focuser makes this an ideal choice for imaging. The fast focal ratio enables devices to capture images in less time than slower scopes, while the focusing mechanism gives it the ability to achieve tack-sharp focusing with zero backlash that rack-and-pinion focusers are generally unable to accomplish. This 2" focuser will accept larger eyepieces so users can enjoy a truly immersive visual experience and will ensure larger imaging sensors are completely covered.

Integrated micro-stepper motors and a worm-wheel/timing belt transmission move the optical tube assembly smoothly without vibrations. Digital encoders on each axis keep track of the mount's position, even when moved manually, to maintain its alignment for easier usability. Controlling the mount is the SynScan computer hand controller. Outfitted with a database of over 42,900 objects including the sun, Moon, planets, galaxies, nebulae, and stars, the controller features multiple alignment procedures to help get users observing faster. A Deep Sky Tour takes users on an automatic tour of the night sky, showing them the best celestial objects overhead on any given day and time. Periodic Error Correction (PEC), Pointing Accuracy Enhancement (PAE), and anti-backlash compensation functions aid the user to correct the play between gears and the intrinsic errors in the mount and software to improve tracking, slewing, pointing, and GoTo accuracy over time. The intuitive menu-driven system is easy to use by beginners and experienced users alike.

Optical Tube
  • 18" (457.2mm) aperture
  • f/4.2 focal ratio
  • 1900mm effective focal length
  • Dobsonian reflector light path
  • Fused borosilicate mirror glass allows for thinner mirrors that reduce weight and increase cooling
  • Highly reflective aluminum mirror coatings
  • 120mm secondary mirror, 7% obstruction by area
  • Resolution: 0.31 (Rayleigh); 0.25 (Dawes)
  • Dual-speed Crayford-style focuser enables more precise focusing than conventional rack-and-pinion without backlash
  • Max eyepiece height: 74.5" (189.2 cm), when OTA is pointed at the zenith
  • Open truss tube design allows for easier breakdown and transportation, with reduced weight versus solid tubes
SynScan Hand Controller
  • Wired hand-held computer controller for mount
  • Intuitive menu-driven system
  • 42,900-object database including 25 user-defined objects
  • Deep-Sky Tour takes user on a tour of the best deep-sky objects visible on any day and time
  • Alignment assistance: One/two/three-star, brightest star, daytime align, polar align
  • Tracking rates: Sidereal, solar, lunar
  • Nine slew speeds: 0.5x, 1x, 8x, 16x, 32x, 64x, 128x, 400x, 600x, 800x (3.4°/sec)
  • Periodic Error Correction (PEC) improves tracking accuracy for long-exposure astrophotography
  • Anti-backlash compensation trains out the inherent play between gears to improve GoTo, slew, and tracking accuracy
  • Pointing Accuracy Enhancement (PAE) allows users to correct pointing accuracy errors for improved GoTo and pointing over time
  • Connect to a computer via user-supplied RS-232 cable
  • Flash upgradable via internet download
  • 2-line, 18-character long LCD variable intensity LCD screen, 19 backlit control keys

Database Details:

  • Solar system including Moon, sun, and planets
  • Named stars
  • NGC catalog
  • IC catalog
  • Messier catalog
  • Caldwell catalog
  • SAO catalog
  • Named stars, double stars, variable stars
  • Motorized alt-azimuth
  • 0.9°/step hybrid stepper motor
  • Dual-axis digital encoders ensure accurate tracking while allowing mount to be moved manually without compromising alignment
  • Steel and Teflon azimuth and altitude bearings enable smooth movement with limited vibrations
  • Floor standing with adjustable feet for proper leveling
  • Included three 2.3-pound (1kg) counterweights enable precise balancing, especially when using accessories such as heavy eyepieces or imaging rigs
  • Weight: 155 pounds, fully assembled with counterweights
Included Accessories
  • 1.25" 10mm eyepiece yields 190x power, accepts most 1.25" astronomical filters
  • 2" long eye relief 28mm eyepiece produces 68x magnification, accepts most 2" astronomical filters
  • 1.25" collimation eyepiece enables the user to properly collimate the primary and secondary mirrors
  • 2"-to-1.25" reducer adapter allows the use of smaller eyepieces and accessories in the larger drawtube
  • 9x magnification ensures a wide field of view for faster alignment and easier star-hopping navigation
  • Large 50mm objective enables it to resolve dimmer objects
  • Covers the open portion of the truss assembly
  • Ribbed fabric absorbs internal reflected light
  • Blocks peripheral exterior and reflected interior light which can interfere with light transmission to the mirrors
  • Helps to produce higher contrast views and sharper images during astrophotography
In the Box
Sky-Watcher Stargate 18" f/4.2 Truss-Tube GoTo Dobsonian Telescope
  • SynScan Hand Controller
  • 9x50 Finderscope
  • 2" 28mm Eyepiece
  • 1.25 " 10mm Eyepiece
  • 1.25" Collimation Eyepiece
  • Eyepiece Reducer Adapter
  • Ribbed Fabric Shroud
  • 3 x 2.3-lb Counterweights
  • Limited 2-Year Warranty
  • Table of Contents
    • 1Description

    Sky-Watcher Stargate specs

    Optical Design Dobsonian reflector
    Aperture 18" / 457.2mm
    Focal Length 1900 mm
    Focal Ratio f/4.15
    Motors Hybrid stepper motor
    GoTo System SynScan hand controller
    Eyepiece Barrel Diameter 2"
    1.25" with included adapter
    Diagonal None
    Finderscope 9 x 50
    Tripod None
    Mount Type Motorized alt-az
    Power Requirements 15VDC, 3A
    Optical Tube Dimensions Height: 80.7" / 205.0 cm
    Horizontal radius: 57.1" / 145.0 cm
    Base diameter: 23.2" / 59.0 cm
    Weight Upper Cage: 11.0 lb / 5.0 kg
    Truss Poles: 16.0 lb / 7.3 kg, total; 2.6 lb / 1.2 kg, each
    Mirror Box: 62.0 lb / 28.1 kg
    Dobsonian Base: 66.0 lb / 29.9 kg
    Fully Assembled: 155.0 lb / 70.3 kg, with weights

    Sky-Watcher Stargate reviews

    Be the first to review this item

    Sky-Watcher Stargate Q&A

    Sky-Watcher Stargate accessories

    See any errors on this page? Let us know.