Sky-Watcher Skyliner 300P FlexTube SynScan GoTo - Dobsonian Telescope

The Sky-Watcher Skyliner 300P FlexTube SynScan combines a large 305 mm aperture, a fully motorised Dobsonian mount and SynScan GoTo technology with a collapsible FlexTube optical-tube design for easier transport and storage.

Its 305 mm parabolic primary mirror and 1500 mm focal length provide an f/4.92 focal ratio. This large aperture is particularly suitable for visual deep-sky astronomy while also offering excellent capabilities for detailed lunar and planetary observation.

The Dobsonian base incorporates heavy-duty servo motors, the SynScan computerised control system and built-in Wi-Fi. Following a simple alignment procedure, the telescope can automatically slew to thousands of celestial objects.

Two control methods are available. The supplied SynScan handset includes a database of more than 42,900 objects, while the built-in Wi-Fi allows the telescope to be controlled wirelessly through the free SynScan application for iOS and Android devices.

Patented Freedom-Find dual-encoder technology also allows the telescope to be moved manually without losing alignment or positional information. The observer can therefore push the telescope close to a distant part of the sky and allow the GoTo system to perform the final positioning.

The FlexTube design substantially reduces the size of the optical tube without requiring the assembly and disassembly associated with a conventional truss-tube telescope. Three rigid support poles allow the tube to be extended or collapsed in seconds.

When fully extended, the structure is designed to maintain telescope rigidity and collimation.

A separate slightly shorter locking position is also provided for binoviewer use.

The optical tube can be quickly separated from the motorised base, allowing the two main sections to be transported independently.

305 mm Aperture

Primary mirror diameter:

• 305 mm

This aperture provides substantial light-gathering capability for visual astronomy.

Compared with a 250 mm telescope, the Skyliner 300P provides:

• 44% more light gathering

This difference is particularly valuable when observing faint deep-sky targets.

Parabolic Primary Mirror

The primary mirror has a:

• Parabolic figure

This geometry brings incoming light rays to a common focal point and eliminates the spherical aberration associated with spherical mirrors used at fast focal ratios.

The primary mirror is designed to provide sharp, detailed and high-contrast images.

Low-Expansion Borosilicate Glass

The primary and secondary mirrors are manufactured from:

• Low-expansion borosilicate glass

This material has a substantially lower coefficient of thermal expansion than conventional glass.

In practical use this provides:

• Faster cool-down
• Improved mirror-shape stability during cooling
• Reduced thermal distortion
• Earlier observing after moving the telescope outdoors

The system is designed to reach thermal equilibrium more rapidly without relying on a cooling fan.

High-Reflectivity RAQ Coatings

The primary and secondary mirrors use:

• RAQ Radiant Aluminium Quartz coatings

The coating system includes:

• Aluminium
• Dielectric tantalum pentoxide
• Silicon dioxide

Reflectivity reaches:

• 94%

The coating is designed to combine high reflectivity with protection and long-term durability.

Thin Secondary-Mirror Supports

The secondary mirror is supported by four spider vanes.

Vane thickness:

• 0.5 mm

These thin supports are designed to:

• Minimise obstruction of the light path
• Allow more light to reach the primary optical system
• Keep diffraction spikes around bright stars to a minimum

Focal Length and Focal Ratio

Focal length:

• 1500 mm

Focal ratio:

• f/4.92

This combination provides a large aperture with a focal length suitable for both deep-sky and lunar or planetary observation.

Deep-Sky Observation

The 305 mm aperture is particularly suitable for visual deep-sky astronomy.

Targets include:

• Galaxies
• Nebulae
• Star clusters

The large primary mirror provides enough light-gathering capability to reveal many faint objects and additional detail compared with smaller-aperture telescopes.

Lunar and Planetary Observation

The Skyliner 300P FlexTube SynScan is also suitable for observing:

• Moon
• Planets

The combination of large aperture and parabolic primary mirror allows high magnifications to be used when atmospheric conditions permit.

Collapsible FlexTube System

The FlexTube system uses:

• 3 rigid support poles
• 3-point tube locking system
• Fully retractable optical tube

The tube can be extended or collapsed in seconds without assembling a separate truss structure.

When extended, the system is designed to prevent:

• Lateral movement
• Excessive flexure
• Loss of collimation caused by deployment

Binoviewer Position

A separate slightly shorter locking position is provided for:

• Binoviewer use

This reduces the optical-tube length when required by this observing configuration.

Tube Dimensions

Extended tube length:

• 1400 mm

Retracted tube length:

• 920 mm

The FlexTube system therefore substantially reduces the size of the telescope for transport and storage.

2-Inch Precision Crayford Focuser

The telescope is equipped with a:

• 2-inch precision Crayford focuser

It accepts:

• 1.25-inch eyepieces
• 2-inch eyepieces

Both adaptors are supplied.

1.25-Inch Adaptor With Brass Compression Ring

The 1.25-inch adaptor uses:

• Brass compression ring

This prevents the locking screws from directly marking the eyepiece barrels.

70° Wide-Angle Eyepieces

Two Super Wide Angle eyepieces are supplied:

• 12.5 mm
• 20 mm

Apparent field:

• 70°

With the telescope's 1500 mm focal length they provide:

• 120x with the 12.5 mm eyepiece
• 75x with the 20 mm eyepiece

Highest Practical Power

Highest practical potential power:

• 610x

Actual usable magnification depends on atmospheric conditions and the observed target.

9x50 Finderscope

The telescope is supplied with a:

• Straight 9x50 finderscope
• Crosshair reticle

It assists with locating and centring objects before viewing them through the main telescope.

Universal Smartphone Adaptor

A universal smartphone adaptor is supplied.

Compatible smartphone width:

• 54 to 90 mm

It allows a compatible smartphone to be positioned behind an eyepiece for capturing celestial objects.

Fully Motorised Dobsonian Mount

The optical tube is supported by an alt-azimuth Dobsonian base incorporating:

• Heavy-duty servo motors
• Computerised control
• GoTo system
• Built-in Wi-Fi
• Accessory tray

Following alignment, the motors can automatically slew the telescope to the selected object.

The drive system is designed for quiet operation.

SynScan GoTo

The supplied SynScan handset contains:

• More than 42,900 objects

Its database includes the complete:

• Messier catalogue
• NGC catalogue
• IC catalogue

Once the mount is aligned, an object can be selected from the database and the telescope automatically slews to its position.

Built-In Wi-Fi

The base includes:

• Built-in Wi-Fi

This allows wireless control from a compatible mobile device.

No additional external Wi-Fi module is required to use the SynScan application.

SynScan Application

The SynScan application is available for:

• iOS
• Android

It allows the GoTo system to be controlled from a smartphone or tablet.

The application database contains more than:

• 10,000 objects

It includes:

• 10,759 deep-sky objects
• Messier catalogue
• NGC catalogue
• IC catalogue
• Caldwell catalogue
• Named deep-sky objects
• 305 named stars
• 55 double stars
• 7 planets
• Sun
• Moon

When working with compatible third-party planetarium software, the number of accessible objects is not limited to the application's internal database.

SynScan Alignment Methods

The application provides several alignment methods:

• 1-star alignment
• 3-star alignment
• Brightest Star alignment
• North-Level alignment

These procedures allow the setup method to be adapted to observing conditions and user preference.

Additional Application Features

The SynScan application also provides:

• Tonight's Best Sky Tour
• Point and Go using a mobile device
• Celestial-object identification
• Remote control over the Internet
• User-defined objects
• Pointing Accuracy Enhancement PAE

These functions extend the system beyond basic GoTo operation.

Freedom-Find Technology

The mount uses patented:

• Freedom-Find dual-encoder technology

This allows the telescope to be moved manually without losing:

• Alignment
• Positional information
• GoTo system reference

When moving to a distant region of the sky, the observer can push the optical tube close to the target and allow the computer to complete the final positioning.

Manual and Motorised Control

The Skyliner 300P FlexTube SynScan can therefore be operated using:

• Manual tube movement
• Motorised GoTo movement

Freedom-Find maintains positional continuity between these two methods.

Easier Transportation

The optical tube can be quickly separated from the motorised base.

The telescope can therefore be transported as:

• Optical tube assembly
• Motorised Dobsonian base

The FlexTube system further reduces the tube length before transportation.

Optical-Tube Weight

OTA weight:

• 21 kg

Motorised Base Weight

Rocker-box weight:

• 24 kg

Separating the tube from the base therefore makes handling considerably easier.

Base Diameter

Base diameter:

• 632 mm

This dimension should be considered when planning transportation and storage.

Power

Power requirement:

• 12 V DC

Polarity:

• Tip positive

Black Diamond Finish

The optical tube uses Sky-Watcher's:

• Black Diamond metallic finish

Contrasting white surfaces are incorporated into the design.

In addition to their appearance, these surfaces improve the visibility of parts of the telescope in darkness and can help prevent accidental contact during nighttime observing.

Technical Specifications

• Manufacturer : Sky-Watcher
• Model : Skyliner 300P FlexTube SynScan GoTo
• Manufacturer product code : 10226
• Optical design : Newtonian reflector
• Mount : Motorised alt-azimuth Dobsonian
• Pointing system : SynScan GoTo
• Primary mirror diameter : 305 mm
• Primary mirror : Parabolic
• Mirror material : Low-expansion borosilicate glass
• Focal length : 1500 mm
• Focal ratio : f/4.92
• Light gathering : 44% greater than a 250 mm telescope
• Mirror coating : RAQ Radiant Aluminium Quartz
• Reflectivity : 94%
• Secondary-mirror supports : 4 spider vanes
• Spider-vane thickness : 0.5 mm
• Supplied eyepieces : 12.5 mm and 20 mm
• Eyepiece apparent field : 70°
• Supplied magnifications : 75x and 120x
• Highest practical potential power : 610x
• Focuser : Precision Crayford
• Focuser size : 2 inch
• Eyepiece adaptors : 1.25 inch and 2 inch
• 1.25-inch adaptor : Brass compression ring
• Finder : Straight 9x50
• Finder reticle : Crosshair
• Smartphone adaptor : Universal
• Compatible smartphone width : 54 to 90 mm
• Optical-tube system : Fully collapsible FlexTube
• Support poles : 3
• Tube locking system : 3 point
• Additional binoviewer position : Yes
• Drive : Heavy-duty servo motors
• Quiet operation : Yes
• Wi-Fi : Built in
• Hand controller : SynScan AZ
• Handset database : More than 42,900 objects
• Handset catalogues : Messier, NGC and IC
• Mobile control : SynScan application
• Application compatibility : iOS and Android
• Application database : More than 10,000 objects
• Deep-sky objects in application : 10,759
• Named stars : 305
• Double stars : 55
• Solar-System objects : 7 planets, Sun and Moon
• Alignment methods : 1-star, 3-star, Brightest Star and North-Level
• Tonight's Best Sky Tour : Yes
• Point and Go : Yes
• Object identification : Yes
• Remote Internet control : Yes
• User-defined objects : Yes
• PAE : Yes
• Freedom-Find technology : Dual encoder
• Manual movement without losing alignment : Yes
• Accessory tray : Yes
• Power : 12 V DC
• Polarity : Tip positive
• Base diameter : 632 mm
• OTA weight : 21 kg
• Rocker-box weight : 24 kg
• Extended OTA length : 1400 mm
• Retracted OTA length : 920 mm

Package Contents

• Sky-Watcher Skyliner 300P FlexTube optical tube
• Motorised SynScan alt-azimuth Dobsonian base
• SynScan AZ hand controller
• 12.5 mm 70° Super Wide Angle eyepiece
• 20 mm 70° Super Wide Angle eyepiece
• Straight 9x50 finderscope with crosshair reticle
• 1.25-inch eyepiece adaptor with brass compression ring
• 2-inch eyepiece adaptor
• Universal smartphone adaptor
• Accessory tray