Refractor-telescoop Skywatcher BK 1309 EQ2 — 130 mm opening, 900 mm brandpuntsafstand

The Skywatcher BK 1309 EQ2 refractor telescope with a 130 mm aperture and 900 mm focal length is designed to offer a compromise between light-gathering capability and manageable focal power. The instrument is supplied on an EQ2 equatorial mount that allows manual polar alignment and tracking, enabling extended visual observation sessions and basic astrophotography when paired with appropriate adapters and accessories. The optical configuration and moderate focal ratio make the telescope suitable for viewing planets, the Moon, star clusters and brighter deep-sky objects.

Advantages

The telescope combines a large 130 mm objective with a 900 mm focal length to deliver improved resolution and increased brightness compared with small-aperture refractors, while remaining compact enough for transport and setup. The EQ2 equatorial mount simplifies sidereal tracking after polar alignment and supports smooth manual motion in right ascension and declination. The optical design provides a useful balance for both high-contrast planetary details and wide-field views of extended objects when used with suitable eyepieces.

Suitable for

• Visual observation of the Moon and planets
• Viewing star clusters, double stars and brighter nebulae
• Amateur astrophotography with DSLR or mirrorless cameras using compatible adapters
• Beginner to intermediate amateur astronomers learning polar alignment and manual tracking

Key specifications

• Aperture: 130 mm optical objective for increased light collection
• Focal length: 900 mm suitable for a variety of eyepiece focal lengths
• Mount type: equatorial (EQ2) for polar alignment and manual sidereal tracking
• Optical design: refractor configuration providing high-contrast images with low maintenance
• Portability: moderate size and weight for transport and field setup

How to use

Set up the telescope on a stable, level surface and assemble the optical tube onto the EQ2 equatorial mount following the manufacturer's mounting points. Perform a rough polar alignment by pointing the mount's polar axis toward the celestial pole, then refine alignment using visible stars and the mount's slow-motion controls. Start observations with a low-power eyepiece to locate targets, then switch to higher-power eyepieces for detail. For basic astrophotography, attach a compatible camera adapter and balance the system on the mount before making long-exposure attempts; use short exposures first to verify framing and focus.

Recommendations

Use the telescope on nights with steady seeing for planetary detail and select higher-contrast eyepieces for lunar and planetary work. Allow the optical tube to thermally acclimate to outdoor temperature to reduce image distortion. When attempting astrophotography, ensure accurate polar alignment and balance, and start with short exposures to confirm focus and tracking before progressing to longer exposures or stacking multiple frames.