The Sharpstar SCA310 is a 310mm large-aperture f/3.8 Super Cassegrain astrograph designed for serious deep-sky astrophotography. Its ultra-fast focal ratio and precision parabolic primary mirror deliver exceptional light-gathering power with sharp, round stars across the entire field.
An integrated 3-inch triplet corrector with ED glass produces a flat, well-corrected image circle suitable for full-frame and medium-format sensors. The carbon-fibre tube ensures excellent thermal stability during long imaging sessions, making the SCA310 ideal for high-resolution, high-efficiency imaging of faint nebulae and galaxies.
Ultra-Fast f/3.8 Optical Design for Deep-Sky Imaging
With a 310mm aperture and fast f/3.8 focal ratio, the SCA310 enables significantly shorter exposure times while revealing fine detail and vivid colour in faint deep-sky targets.
The high-precision parabolic primary mirror eliminates spherical aberration, delivering sharp, round star points across the field. A fused-silica spherical secondary mirror offers excellent thermal stability, folding a long optical path into a compact, rigid tube.
Enhanced aluminium mirror coatings provide over 95% reflectivity, maximising light throughput and imaging efficiency.
A rear-mounted 3-inch triplet coma corrector incorporating ED glass delivers a flat, well-corrected field from centre to edge, fully supporting full-frame and medium-format sensors with near 100% illumination.
The optical design requires no additional back-focus calculations, enabling fast and straightforward setup and focusing.
A hollow carry handle and multi-slot mounting system allow flexible accessory attachment. The supplied 405mm Losmandy-style dovetail ensures secure compatibility with mainstream equatorial mounts.
The 3.5-inch high-rigidity rack-and-pinion focuser provides 28mm of travel with a 1:10 dual-speed fine adjustment. A front-mounted 360° rotator prevents cable wrap during imaging.
Rear adapters (M68 / M54 / M48) ensure wide compatibility. The M48 adapter includes an integrated 2-inch filter thread for direct filter installation.
Three rear-mounted cooling fans accelerate thermal equilibrium of the primary mirror, improving image stability and overall observing efficiency.
How the SCA310 Compares to Other Astrograph Designs
| Design | Typical Characteristics | How the SCA310 Differs |
|---|---|---|
| Ritchey–Chrétien (RC) | Slower focal ratios (typically f/8), large central obstruction, often requires additional flatteners or reducers for imaging. | The SCA310 operates natively at f/3.8 with an integrated ED triplet corrector, delivering a wider, flatter field and dramatically shorter exposure times without extra optics. |
| Corrected Dall–Kirkham (CDK) | Excellent optical correction but generally larger, heavier, and significantly more expensive systems. | The SCA310 achieves high-level correction in a more compact and accessible package, optimised specifically for modern deep-sky imaging sensors. |
| Sharpstar SCA310 | Native f/3.8 system with integrated ED corrector, carbon-fibre tube, active cooling, and full-frame to medium-format support. | Purpose-built for efficient, high-resolution astrophotography with minimal setup complexity and maximum imaging productivity. |
Specifications
| Aperture | 310mm |
|---|---|
| Focal Length / Ratio | 1178mm / f/3.8 |
| Primary Mirror | Aspherical |
| Primary Mirror Material | Pyrex-equivalent glass |
| Secondary Mirror | Fused silica glass |
| Image Circle | Medium format (55mm) |
| Tube Material | Carbon fibre |
| Corrector | Triplet (1× ED glass) |
| Secondary Diameter | 184mm |
| Tube Length | 721mm |
| Tube Diameter | 378mm |
| Weight | 23.5kg |
| Rear Threads | M68 / M54 / M48 (M48 includes filter thread) |
| Back Focus | 38–66mm |
Product Size Diagram
Optical Path Diagram
Relative Illumination
Spot Diagram
