Sky-Watcher K100 Klevtsov-Cassegrain OTA 100/1000

The Sky-Watcher K100 is a compact 100 mm Klevtsov-Cassegrain optical tube. Its catadioptric design folds a 1,000 mm focal length into a tube only 363 mm long. At f/10 it is well suited to lunar and planetary detail, double stars and bright compact deep-sky objects. This is an OTA; mount and tripod are not included.

Compact optics with a Klevtsov corrector

The Klevtsov design combines primary and secondary mirrors with a small corrector lens in front of the secondary. RAQ mirror coatings support high reflectivity and durable surface protection. The long focal length gives approximately 50x and 100x magnification with the supplied 20 mm and 10 mm eyepieces. The manufacturer lists 200x as the maximum useful magnification; atmospheric seeing and target conditions affect the practical limit.

Quick focusing and smartphone imaging

The patented friction focuser moves the primary mirror and has two focus knobs. A distance scale helps you return to focus for nearby objects at about 8 m or 14 m and for infinity. The included smartphone holder enables simple afocal snapshots; the smartphone itself is not included. A 45 mm Vixen-style dovetail bar with 1/4-inch mounting threads allows attachment to a compatible mount.

Package contents and compatibility

The package includes the 100 mm optical tube, 5x24 finder, 10 mm and 20 mm eyepieces, a 1.25-inch diagonal and smartphone holder. Choose a mount that safely supports the tube and has a compatible attachment. Mount, tripod and smartphone are not included.

Technical specifications

Not included: Mount, tripod and smartphone.