Sharpstar SCA260v2 version II - 260mm F5 aspherical Cassegrain Astrograph carbon OTA

Sharpstar-optics is excited to launch the newest Aspherical Cassegrain OTA SCA260 with short focal ratio. This system is to make up for domestic market today. The primary mirror is aspherical with higher grinding difficulty, its production and testing requirements are more complex than traditional primary mirrors. Its carbon fiber tube is lightweight, durable and generous, and the use of like Pyrex materials is more stable than traditional materials.

The primary and secondary mirrors are all made of enhanced aluminum coating, and the reflectivity is guaranteed to be above 95%. The secondary mirror has a new lever adjustment function that can be moved in a horizontal position. The 3-inch dedicated focuser ensures smooth operation without slipping when astrophotography with accessories.

All CNC aluminum parts and novel hollow handles can be connected to different accessories, and the appearance and mechanical quality are of high standards design to meet the wants and needs of today's demanding astronomer.

The optical path includes a triplet 3" field flattener, combining the system ensures full-frame photography and vignetting control. The two M54×0.75 threads and M48×0.75 threads at the rear of the focuser can meet different needs, are convenient to connect to most commercially available imaging-terminal and achieve perfect focus.

Optimized SCA260 version II

The optimized SCA260 is still designed with aspherical mirror which entails much more sophisticated research and development. The process of producing, manufacturing and testing is more complicated compared with that of an ordinary reflective mirror and the Pyrex-like material used is more stable than those traditionally used. The telescope is wrapped with durable carbon fiber material which is lightweight, durable and beautiful.

Both the primary and secondary mirrors of SCA260 wear enhanced aluminum coatings, which ensure they can achieve a high reflectivity of more than 95%. We further simplify the optical axis mechanical structure, only need to adjust the secondary mirror pull rod to adjust the secondary mirror.

A 3" large corrector, featuring a three-element lens structure, is laid in the optical path, enabling the whole optical system to better achieve full-frame imaging and control the vignette.

The delicately pierced handle bar is completely made from CNC-manufactured aluminum, which can be used as a base for the attachment of other accessories, optimizing the supporting mechanical construction and decreasing its weight.

Based on the original, we have upgraded the travel length of the 3" dedicated focuser to 50mm for greater practicability. We have also upgraded the load of the focuser to allow you to add the accessories as you like, ensuring no slippage and smooth operation when shooting with accessories.

We also added a 360° rotator at the rear back of the focusing device, so we don't have to worry about the EAF data line getting entangled in the process. Three section M68X0.1 thread, M54 × 0.75 thread and M48 × In the 0.75 thread adapter ring, a built-in 2-inch filter thread is added to meet different needs, facilitate connection to most imaging terminals on the market and perfect focusing.

Specifications

• Primary mirror aperture: 260mm
• Focal length/focal ratio: 1300mm / F5
• Primary mirror type: aspherical reflector
• Primary mirror material: PZ33 (same as pyrex glass)
• Corrector rear group combination: three-element air-spaced
• Minor axis diameter of the secondary mirror: 120mm
• Secondary mirror type: spherical
• Image circle range: 80mm
• Tube material: carbon fiber
• Outer diameter of tube: 304mm
• Tube length: 712mm
• Tube weight: 14.5kg
• Resolution: 0.46
• Focuser: 3.35 inch
• Visual limiting magnitude: 13.8
• Back focus: 70mm (calculated from the end of M48 thread)