SharpStar SCA260 V2 260mm f/5 Super Cassegrain Astrograph

260mm f/5 Optics with an 80mm Corrected Image Circle

At the heart of the SCA260 V2 is a 260mm aspherical primary mirror made from PZ33, a Pyrex-like glass with excellent thermal stability. Paired with a three-element air-spaced corrector, this f/5 system illuminates an enormous 80mm image circle, free of significant vignette or distortion. This makes the SCA260 V2 fully compatible with the largest professional CMOS and CCD sensors available, including those with diagonals exceeding 60mm.

• Aspherical Primary Mirror: Provides superior correction compared to standard spherical mirrors, critical for achieving sharp focus across the large imaging field.
• Enhanced Aluminum Coatings: Both the primary and 120mm minor axis secondary mirror feature coatings that ensure high reflectivity for brighter images and reduced exposure times.
• Full-Frame and Beyond: The 80mm image circle provides ample coverage for full-frame (43mm diagonal) sensors and larger medium-format chips without requiring a separate reducer or flattener.

14.5kg Carbon Fiber Tube and Simplified Collimation

The optical tube is constructed from carbon fiber, which provides a high stiffness-to-weight ratio and minimizes thermal expansion and contraction during long imaging sessions. This ensures focus remains stable as ambient temperatures change overnight. The total tube weight of 14.5kg places it within the payload capacity of many mid-to-high-end equatorial mounts.

SharpStar has engineered the collimation mechanics for field accessibility. Unlike traditional Cassegrain designs that require complex adjustments, the SCA260 V2's optical alignment is primarily controlled by adjusting the secondary mirror's pull rod, simplifying the process of achieving perfect star shapes.

3.35" Focuser with 70mm of Back Focus

The SCA260 V2 is equipped with a heavy-duty 3.35" rack and pinion focuser designed to carry professional imaging trains without flexure or slippage. The rear of the focuser includes a 360° rotator for effortless camera framing and a built-in 2-inch filter holder. It provides a generous 70mm of back focus distance from the M48x0.75 threaded connection, accommodating filter wheels, off-axis guiders, and other accessories.

• Multiple Connection Threads: The focuser terminates in a versatile adapter system with M68x1, M54x0.75, and M48x0.75 threads to connect to nearly any camera or accessory.
• 360° Rotator: Allows you to frame your target precisely without loosening the camera or introducing tilt into the optical train.
• CNC Handlebar: The integrated handle is not just for carrying; it also serves as a mounting platform for guide scopes or other accessories, further streamlining your setup.