Sporting the large light bucket users have come to expect from a Dob, the Sky-Watcher Flextube 8" f/6 GoTo Collapsible Dobsonian Optical Tube Assembly gives users great performance at a reasonable price. Its large parabolic Borosilicate primary mirror is treated with a combination of quartz, titanium, and silicon dioxide that brings its reflectivity to over 94%, with a secondary mirror obstruction of just 6% by area. Unlike traditional Dobsonians that tend to be bulky and unwieldy, the Flextube's patented truss design allows it to retract to just 33" for easier transport and storage, and then extends to 44" for observation.
The large 8" aperture draws in copious amounts of light to resolve awe-inspiring deep-sky objects like wispy nebulae and galaxies, while also revealing incredible details of the lunar surface and planetary features. Its fast f/6 focal ratio and Crayford focuser makes this an ideal choice for imaging. The fast focal ratio enables devices to capture images in less time than slower scopes, while the focusing mechanism gives it the ability to achieve tack-sharp focusing with zero backlash that rack-and-pinion focusers are generally unable to. This 2" focuser will accept larger eyepieces so users can enjoy a truly immersive visual experience and will ensure larger imaging sensors are completely covered. For convenience, Sky-Watcher includes a reducer adapter that will allow you to use the more common 1.25" eyepieces.
- Large 8" (203mm) aperture is able to resolve dim deep-space objects like wispy nebulae and galaxies
- Fast f/5.9 focal ratio ensures a wide field of view, maximum light throughput
- For astrophotography the fast focal ratio will result in shorter exposure times versus "slower" OTAs while achieving similar results
- Long 1200mm focal length helps to produce the fast focal ratio and moderate magnification potential
- Collapsible truss system saves space during transport and storage, measuring just 33" when trusses are retracted and extending to 44" when set up
- Borosilicate parabolic primary mirror
- Quartz, titanium, and silicon dioxide mirror coatings bring the reflectivity to 94%
- Resolution: 0.57 arcsec (Dawes Limit), 0.69 arcsec (Rayleigh Limit)
- 48mm secondary diameter mirror; Obstruction: 24% by diameter, 6% by area
- 47" eyepiece height when aimed directly overhead at the zenith
- 9.375" (23.81cm) outside tube diameter
- Crayford-style is much more precise than the traditional rack-and-pinion
- Tension control system eliminates gears, resulting in zero backlash for tack-sharp focus on dim objects or objects, like binary stars, that are close together
- 2" diameter holder allows the use of larger eyepieces and imaging systems that provide a wide field of view and long eye relief to make viewing dim and small deep-sky objects more comfortable
- 1.25" diameter nosepiece accepts most standard filters
- 25mm focal length eyepiece produces a low 25x magnification for wide-field observations, alignment, and viewing lunar surface details
- 10mm focal length eyepiece yields a high 120x power to make detailed observations of specific portions of the sky or for planetary viewing
- 2-to-1.25" reducer allows the use of the more common size eyepieces and accessories
- Low 9x power produces a wide field of view for accurate alignment
- 50mm objective allows users to see dimmer stars for more options during 2-star alignment
- Mounting bracket included