Sky-Watcher Explorer 200PDS

Designed for prime-focus astrophotography while retaining excellent visual observing capabilities, the Sky-Watcher Explorer 200PDS uses a 203 mm parabolic Newtonian optical system with a 1000 mm focal length and f/5 focal ratio.

Its low-expansion borosilicate mirrors, dual-speed 2-inch Crayford focuser and rigid internally darkened tube are among the main features of this imaging-oriented PDS design.

203 mm Parabolic Primary Mirror

The primary mirror has a diameter of 203 mm and a parabolic surface.

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

Sky-Watcher specifies diffraction-limited optics designed to produce sharp, high-contrast and detailed images.

Low-Expansion Borosilicate Mirrors

Both primary and secondary mirrors are manufactured from low-expansion borosilicate glass.

This material allows the mirrors to reach thermal equilibrium more quickly and helps them retain their correct shape during the cooling process.

1000 mm Focal Length and f/5 Focal Ratio

With a 1000 mm focal length and 203 mm aperture, the Explorer 200PDS operates at approximately f/5.

This configuration is suitable for both deep-sky imaging and visual observation of a wide range of astronomical objects.

2-Inch Dual-Speed Crayford Focuser

Focusing is provided by a 2-inch dual-speed Crayford focuser.

The 10:1 reduction system allows rapid coarse adjustment followed by much more precise fine focusing, particularly useful for astrophotography.

The focuser also incorporates an M54 internal thread.

1.25-Inch and 2-Inch Compatibility

Adapters for both 1.25-inch and 2-inch eyepieces are supplied.

This provides compatibility with a wide range of astronomical eyepieces and accessories.

Radiant Aluminum Quartz RAQ Coating

The primary and secondary mirrors feature Sky-Watcher Radiant Aluminum Quartz RAQ coatings.

The coating system combines reflective aluminium, a dielectric tantalum pentoxide layer designed to improve reflectivity and durability, and a protective silicon dioxide layer.

Sky-Watcher specifies 94% reflectivity.

58 mm Secondary Mirror

The secondary mirror has a 58 mm minor axis.

It is supported by four 0.5 mm thin spider vanes designed to minimise obstruction of the optical path and reduce diffraction spikes.

Fully Collimatable Optics

Both primary and secondary mirrors are fully collimatable.

The primary mirror cell incorporates large knurled adjustment knobs allowing collimation to be carried out conveniently.

Rigid Internally Darkened Tube

The optical tube is manufactured from rolled steel and features an internally darkened finish.

This construction helps reduce unwanted internal reflections while maintaining good mechanical rigidity.

Optional Coma Corrector

Sky-Watcher offers an optically matched M48 coma corrector for this range to optimise star shapes towards the edge of the field in astrophotography.

The coma corrector is available separately.

28 mm LET Eyepiece

A 28 mm 2-inch LET eyepiece is supplied with the optical tube.

It provides approximately 36× magnification with the Explorer 200PDS's 1000 mm focal length.

9 × 50 Finderscope

A fully multi-coated 9 × 50 optical finderscope is supplied.

It incorporates a crosshair reticle and centring bracket for alignment with the main telescope.

Mounting

The optical tube is supplied with tube rings and a 45 mm dovetail bar.

Its stated weight is 8.75 kg.

Sky-Watcher specifically lists mounts including the AZ-EQ5 Pro, HEQ5 Pro, HEQ5-R Pro, EQ6-R Pro, AZ-EQ6 Pro, Wave-100i and Wave-150i as suitable options.

Technical Specifications

• Manufacturer : Sky-Watcher
• Model : Explorer 200PDS
• Product code : 10220
• Type : Newtonian telescope optimised for imaging
• Primary mirror diameter : 203 mm
• Primary mirror : Parabolic
• Focal length : 1000 mm
• Focal ratio : f/5
• Mirror material : Low-expansion borosilicate glass
• Secondary mirror diameter : 58 mm
• Mirror coating : Radiant Aluminum Quartz RAQ
• Stated reflectivity : 94%
• Secondary mirror supports : Four 0.5 mm vanes
• Focuser : Crayford
• Focuser size : 2 inch
• Reduction ratio : 10:1
• Focuser internal thread : M54
• Eyepiece compatibility : 1.25 inch and 2 inch
• Supplied eyepiece : 28 mm 2-inch LET
• Magnification with supplied eyepiece : 36×
• Highest practical power stated : 400×
• Finder : 9 × 50 with crosshair reticle
• Collimation : Adjustable primary and secondary mirrors
• Optical tube : Internally darkened rolled steel
• Dovetail : 45 mm
• Camera adapter : Included
• Optical tube weight : 8.75 kg
• Stated light gathering compared with 150 mm : +77%

Package Contents

• Sky-Watcher Explorer 200PDS optical tube
• Tube rings
• 45 mm dovetail bar
• 28 mm 2-inch LET eyepiece
• 9 × 50 finderscope with crosshair reticle
• 1.25-inch eyepiece adapter
• 2-inch eyepiece adapter
• Camera adapter