Sky-Watcher Evostar ED APO 72mm f/5.8 Refractor Guidescope (OTA Only)

Use the Sky-Watcher Evostar ED APO 72mm f/5.8 Guidescope to improve the precision of your autoguiding system, for wide-field astrophotography with small CCD imagers, or as an exceptional grab-and-go option for fast observation sessions.

The 72mm aperture is complemented by an extra low-dispersion (ED) element set in a doublet apochromatic lens design. These two optical features make the Evostar much more precise than standard refractors and guidescopes, producing crisp and clear high-resolution views with limited edge distortion and accurate color representation. To achieve the sharpest focus possible, Sky-Watcher utilizes a Crayford-style focuser. Unlike a conventional rack-and-pinion system, the focuser utilizes a toothless friction mechanism that smoothly moves the drawtube without the backlash that rack-and-pinion focusers suffer from. The focuser has a large 2" drawtube to accommodate full-frame imaging sensors without vignetting.

A mounting cradle-ring assembly clamps over the OTA and lets the user adjust the orientation and position of the scope relative to the mount to optimize viewing comfort and to help with balancing, while avoiding interference with other equipment. The scope is offered without a mount or tripod, but a Vixen-style dovetail plate makes it compatible with any mount head with a Vixen-style saddle. To protect the optical tube and accessories during transport and storage, a hard aluminum carrying case is provided.

Uses

• Autoguider scope: The optical performance improves the precision of autoguiding systems by being able to finely focus the field and resolve guide-stars better
• Wide-field astrophotography: Using 2" or 1.25" imaging systems directly in the drawtube enables tack-sharp and highly resolved wide-field images of the night sky, galaxies, constellations, and other objects
• Visual: Its optical performance, short focal length, and mounting rings make it an ideal fast grab-and-go option for planetary and lunar observation

Optical Tube Assembly

• 72mm aperture is especially useful for lunar and planetary use
• Short 420mm focal length helps to maintain a short form factor and produce a fast focal ratio
• Fast f/5.8 focal ratio reduces the exposure times required during astrophotography to capture bright and clearly resolved images versus smaller optical systems
• Apochromatic doublet lens design with an extra low-dispersion element eliminates chromatic and spherical aberrations for true color rendition and without distortion across the entire field of view
• Hard aluminum carrying case

Focuser

• Dual-speed Crayford-style
• Crayford focusers use a toothless friction system that allows for super-fine precision focusing without backlash
• Large 2" drawtube prevents vignetting when using wide-field eyepieces for viewing, or large imaging sensors for astrophotography

Mounting

• OTA only, mount head and tripod required for proper use
• Cradle-ring assembly for dovetail plate allows the scope orientation to be changed based on mount configuration
• Vixen-style dovetail plate is compatible with any alt-az or equatorial mount with a Vixen-style saddle
• Weight: 4.3 pounds

EAN: 050234111805