Sky-Watcher Dobson 12" Pyrex 305/1500 Telescope (SW-1304)

Sky-Watcher is a global leader in telescope manufacturing, especially renowned for their Dobsonian-mounted Newtonian telescopes. The company has long prioritized high-quality optics, which is reflected in the stunning views their telescopes provide and the many positive reviews they receive worldwide. With experience dating back to 1990, Sky-Watcher produces Dobsonians in an elegant, mature, and classic form that is both economical and accessible. Although there are many imitators, no other brand matches Sky-Watcher’s ability to create telescopes that are both optically excellent and affordable.

This model is a large Newtonian reflector telescope with a 12-inch (305mm) aperture and a 1500mm focal length. The optical tube is mounted on a stable Dobsonian alt-azimuth mount. As a fast Newtonian telescope, it is ideal for observing nebulae and deep-sky objects under dark skies. At the same time, the large aperture also enables detailed views of the planets and the Moon. Despite its impressive capabilities, this telescope remains affordable, making it a great choice for beginners and demanding astronomy enthusiasts alike.

Pyrex Primary Mirror
All Sky-Watcher 12” Dobsonians are equipped with a primary mirror made from PYREX glass, which has low thermal expansion. This results in higher image quality compared to mirrors made from standard glass.

Optical System
This telescope uses the classic Newtonian design. The parabolic primary mirror is 305mm in diameter with a focal length of 1500mm, resulting in a fast f/5 focal ratio. Thanks to these specifications, the telescope remains manageable in length while still offering high light-gathering power. The moderate focal length allows for both low magnification, which is comfortable for observing faint deep-sky objects, and high magnification for planetary and lunar observations.

Mount
The optical tube is supported by a Dobsonian alt-azimuth mount, known for its simplicity and stability. The telescope is held in a fork mount, with the entire upper part rotating on a base. The low center of gravity and rigid construction make this setup much more stable than typical equatorial mounts.

Focuser
The telescope features a 2-inch Crayford focuser with a 1.25-inch adapter. The Crayford design ensures smooth, backlash-free focusing. Included are a 2-inch extension tube and a 1.25-inch extension/adapter, to be used one at a time. The focuser is compatible with Sky-Watcher’s autofocuser motors.

Astronomical Observations
A 12-inch (30cm) aperture provides extensive observational opportunities:

Solar System:

• Surface features on the Moon smaller than 1 km

• Detailed sunspots, solar granulation (with appropriate filters)

• All planets of the Solar System

• Phases of Mercury and Venus, atmospheric details on Venus (with gray filter)

• Key surface features and polar caps on Mars

• Jupiter’s atmospheric bands, Galilean moons, and their shadows during transits

• Saturn’s ring structure, including Cassini Division, atmospheric bands, and smaller moons

• Uranus and Neptune as distinct blue disks

• Movements of many asteroids against background stars

• Observation of faint comets, including their structures

Stars:

• Around 6.5 million stars across the sky down to magnitude 16

• Double and multiple stars with separations greater than 0.6"

• Vivid colors of many stars

Deep-Sky Objects:

• All Messier objects, hundreds of NGC and IC objects

• Hundreds of globular clusters, many resolved to the core

• Thousands of open clusters with clear structural differences

• Hundreds of nebulae, many with rich detail and dramatic features

• Hundreds of galaxies, including visible disk structures and spiral arms

• Detailed structures in many planetary nebulae, enhanced further with nebula filters

• Subtle features in supernova remnants

With a mirror diameter of 30cm, objects appear much clearer and finer details are visible than in 150mm or 200mm telescopes. However, such a large telescope is more sensitive to light pollution, air pollution, atmospheric stability (seeing), and precise optical collimation. For the best performance, these factors should be considered when using telescopes of 20cm and above. The f/5 focal ratio also makes the quality of eyepieces particularly important.

Terrestrial Observing

This type of telescope is not ideal for terrestrial (land) viewing. To achieve an upright image, a special erecting lens is required. With an erecting lens and the Dobsonian mount, the telescope can function as a simple terrestrial viewing instrument. The Dobsonian mount’s ease of movement and rigidity makes it suitable for following airplanes at cruising altitudes.

Note: The main mirror is shipped separately from the optical tube for safety and size reasons. The mirror comes pre-mounted in its cell, ready for installation.

Included Accessories

• 2-inch adapter

• 9x50 finder scope

• Smartphone adapter

• 12.5mm Wide Angle 70° eyepiece

• 20mm Wide Angle 70° eyepiece

Specifications

Catalog Number: SW-1304
Optical Design: Newtonian Reflector
Mount Type: Dobsonian
Aperture: 305 mm
Focal Length: 1500 mm
Focal Ratio: f/4.9
Limiting Magnitude: 15.0
Maximum Useful Magnification: 610x
Maximum Resolution (Rayleigh): 0.47"
Maximum Resolution (Dawes): 0.38"
Light Gathering Power: 1898x
Tube Weight: 15 kg
Mount Weight: 19 kg
Total Weight: 34 kg
Tube Length: 1400 mm
Tripod Type: Dobsonian
Tripod Height: 740 mm
Mount Control: Manual
Focuser Type: Crayford
Focuser Diameter: 2"
Focuser Micro-motion: No
Secondary Mirror Diameter: 70 mm
Warranty: 60 months