Sharpstar SCA310 Cassegrain The SCA310 is a 310mm large-aperture Cassegrain reflector. It features a fast f/3.8 focal ratio, powerful light-gathering capability, and a wide imaging field, showing excellent performance for deep-sky astrophotography.à With a 310mm aperture and a fast f/3.8 focal ratio, the SCA310 captures light with exceptional efficiency. This allows for significantly shorter exposure times and enhanced productivity in deep‑sky astrophotography, revealing fine details and vivid colors even in faint nebulae. The SCA310 is a Cassegrain reflector whose primary mirror features a high-precision parabolic design. This aspheric mirror demands exceptional grinding and testing techniques to effectively eliminate spherical aberration, ensuring sharp, round star points. Its matching spherical secondary mirror is made from fused silica glass, offering outstanding thermal stability. Achieve long focal length optical path folding within a compact lens tube—delivering both high performance and excellent portability. The primary and secondary mirrors are coated with enhanced aluminum, ensuring a reflectivity of over 95%, fully boosting the efficiency of light utilization. A 3-inch, triplet coma corrector is integrated at the rear of the lens tube, including 1 piece of ED glass, which effectively corrects field curvature and coma to deliver sharp, round stars from the center to the edges of the frame. The SCA310 is specially optimized for medium format and fully covers the full-frame sensors, providing nearly 100% illumination and a flat image field even when shooting with full-frame sensor cameras. The SCA310’s optical structure has been carefully optimized. It does not require additional calculation of back focus when shooting， enabling quick and effortless focusing， which greatly simplifies the imaging process. The lens tube uses a lightweight and robust carbon fiber material. This not only effectively reduces the overall weight but also possesses excellent structural stability and temperature adaptability, preventing focus shift caused by thermal expansion and contraction， ensuring consistent imaging performance. The top is equipped with a hollow handle for easy handling; the multi-hole slotted design facilitates the installation of various expansion accessories. The bottom is equipped with a 405mm long Losmandy-style dovetail plate, compatible with mainstream equatorial mounts. Constructed using full CNC processing, the thickened and widened design ensures stable and reliable installation. The 3.5-inch high-rigidity rack-and-pinion focuser has an upgraded focusing travel of 28mm, providing a greater focusing range. The dual-speed adjustment knob supports 1:10 fine focusing. The load capacity is further enhanced; even when loaded with multiple accessories, it maintains stable and smooth operation, eliminating slippage. The focuser is equipped with a front-mounted 360° rotator, effectively preventing cable wrap during use. The rear features multiple threaded adapters (M68/M54/M48), ensuring seamless compatibility with a wide range of mainstream imaging equipment for precise and effortless focusing. The M48 adapter includes a built-in 2-inch filter thread, allowing for direct filter attachment during shooting. The SCA310 also integrates three efficient cooling fans at the rear. This fan can be activated before observation to rapidly cool the primary mirror, accelerating thermal equilibrium and significantly enhancing both observing efficiency and the overall user experience. Choose the SCA310 to begin an efficient, stable, and deeply rewarding journey into deep-space exploration. Technical Specifications Aperture size 310mm Focal length/Focal ratio 1178mm/F3.8 Primary mirror type Aspherical primary mirror Primary mirror material Similar to Pyrex glass Secondary mirror material Fused silica glass Image circle Medium format(55mm) Tube material Carbon fiber Corrector type Triplet design (including one ED glass) Secondary mirror diameter 184mm lens tube outer diameter 378mm lens tube total length 721mm Gross weight 23.5kg Resolution 0.37 Rear-end thread type M48( (with M48×0.75 filter thread))/M54/M68 adapters Rear-end connection distance Support 38-66mm range In the Box SharpStar SCA310 optical tube assembly Losmandy-style dovetail plate User documentation Warranty Sharpstar's Warranty
