Dobsonian telescope Skywatcher 10" Flex Tube 254/1200 with 1200mm focal length and 254mm aperture

The Skywatcher 10" Flex Tube 254/1200 Dobsonian is a Newtonian reflector telescope with a 254 mm aperture and a 1200 mm focal length, mounted on a simple and stable Dobsonian alt-azimuth base. The optical configuration and large aperture provide substantial light-gathering ability for observing faint deep-sky objects, while the medium focal ratio balances wide-field views and planetary detail. The Flex Tube design allows the optical tube to collapse for more compact transport and extend quickly for observing sessions.

Advantages

The combination of a 254 mm primary mirror and a 1200 mm focal length gives high resolution and improved contrast for galaxies, nebulae and star clusters, as well as suitable magnification for lunar and planetary detail. The Dobsonian mount offers a low center of gravity and intuitive manual pointing, reducing setup complexity and making the telescope accessible to beginners and experienced observers alike. The collapsible tube increases portability without altering optical performance.

Suitable for

• Visual observation of deep-sky objects (nebulae, star clusters, galaxies)
• Lunar and planetary observation with medium to high magnification
• Amateur astronomy sessions and public observing nights
• Portable backyard observing and seasonal travel to dark-sky sites

Key specifications

• Aperture: 254 mm (primary mirror diameter)
• Focal length: 1200 mm
• Focal ratio: f/4.7
• Optical design: Newtonian reflector
• Mount type: Dobsonian alt-azimuth
• Tubing: Collapsible (Flex Tube) for compact storage and transport
• Primary benefits: High light-gathering power and stable manual tracking

How to use

Set the Dobsonian base on a level, stable surface and extend the Flex Tube to its observing position. Attach an appropriate eyepiece in the focuser to achieve the desired magnification; start with a low-power eyepiece to locate objects, then switch to higher power for planetary detail. Use the altitude and azimuth motions of the Dobsonian mount to point and manually track targets. Allow the telescope to reach thermal equilibrium with the outside air for best image quality before detailed observing.

Usage recommendations

For deep-sky observing, use a wide-field eyepiece and consider a light shroud to reduce stray light when the Flex Tube is extended. For planetary work, choose higher-power eyepieces and allow sufficient cooling time. Store the telescope collapsed in a dry environment when not in use and transport it with tube secured to the base to protect optical alignment.