Refractor OTAW telescope Skywatcher BKP 250/1200 Dual Speed — 250mm aperture, 1200mm focal length

The Skywatcher BKP 250/1200 OTAW Dual Speed is a refractor telescope optical tube assembly with a 250 mm aperture and 1200 mm focal length. The OTAW configuration concentrates on optics and focuser performance: a large objective delivers enhanced light-gathering capability and improved resolving power for both deep-sky objects and planetary detail. The dual-speed focuser provides coarse and fine adjustment to achieve precise focus for visual observing and camera sensors. The unit is supplied as an optical tube only; mount, tripod and additional accessories are available separately, allowing flexible system configuration for different observing needs.

Advantages

The large 250 mm aperture increases contrast and detection of faint nebulae and galaxies while maintaining a manageable tube length at 1200 mm focal distance. The dual-speed focuser offers smooth mechanical control with a high-resolution fine focus for critical focus in astrophotography and high-magnification visual work. The optical design balances portability and performance, making the tube suitable for both dedicated observing sessions and transport to dark-sky sites. Mechanical construction emphasizes rigid tube support and stable focuser movement, reducing image shift during focusing and camera adjustments.

Suitable for

• Deep-sky observation of nebulae, star clusters and galaxies
• Planetary and lunar observing at medium to high magnifications
• Astrophotography with dedicated cameras and imaging trains
• Visual astronomy for clubs, field trips and backyard use

Key specifications

• Optical type: refractor OTAW configuration
• Aperture: 250 mm
• Focal length: 1200 mm
• Focal ratio: f/4.8 (approximate based on aperture and focal length)
• Focuser: dual-speed (coarse and fine focus control)
• Primary use: visual observation and astrophotography
• Construction: rigid optical tube designed for stable mounting and reduced image shift

How to use

Install the OTAW tube onto a compatible equatorial or alt-azimuth mount that can safely carry the weight and moment of a 250 mm refractor. Balance the assembly with appropriate counterweights if using an equatorial mount. Attach the desired diagonal, eyepiece or camera adapter to the focuser and use the coarse knob to bring objects into view, then refine focus with the fine-speed control. For imaging, ensure the imaging train is well-balanced and check backfocus distance required by the camera and adapters. Always secure all fittings before slewing the mount.

Usage recommendations

For best results in deep-sky imaging, pair the OTAW with a tracking mount capable of accurate guiding and a field flattener or reducer if using large-area sensors. For high-resolution planetary work, allow the optics to reach thermal equilibrium with ambient temperature and use the fine-speed focuser to achieve critical focus. Regularly check and tighten focuser and accessory fittings to minimize flexure.