Corvane Brisk 76 reflector, tube with equatorial mount

Specifications

Description

The Brisk 76 is a Newtonian reflector with a 76 mm parabolic primary mirror and 380 mm of focal length, which gives a focal ratio of f/5. That ratio produces a wide true field for scanning the Milky Way and large nebulae with a 25 mm eyepiece, while a 6 mm eyepiece still reaches useful magnification on the Moon and bright planets. Jupiter's cloud bands show only faint detail at this aperture, so the telescope suits broad views rather than fine planetary study.

The optical tube is a steel tube with a vented rear cover, so the mirror cools toward outdoor air within about an hour. The secondary mirror sits on a four-vane spider, which adds small diffraction spikes to bright stars. Collimation is set with three thumbscrews at the back of the mirror cell, and a simple laser collimator makes the first alignment straightforward for a beginner.

The 1.25 in rack-and-pinion focuser holds standard eyepieces, and the 6x30 finder with a spring-loaded bracket mounts on the tube. The focuser travel is long enough to reach focus with a 2x Barlow lens. At 2.1 kg, the tube fits a basic alt-az tripod or a small tabletop base without strain. Lock the focus knob before you move the telescope, because the rack gear can shift under a heavy eyepiece.

Under dark skies, typical targets include the Moon, Jupiter with its four largest moons, the Orion Nebula, and the Pleiades, which fill most of a 25 mm eyepiece field. Galaxies such as the Andromeda Galaxy appear as faint, elongated glows, and you will need averted vision to pick out their brighter cores.

About this configuration

The Corvane Brisk 76 reflector is offered in several configurations, and the notes below describe what this particular combination adds or changes. With the equatorial mount, slow-motion controls let you keep a planet centered at high magnification with one hand. Balancing the tube and the counterweight before each session helps the equatorial mount move smoothly in both axes. The carbon fiber tube expands less as the temperature drops, so the focus point drifts less as the night cools.

The starter kit adds two eyepieces and a Barlow lens, which gives you four magnifications from three pieces. This is the 2024 edition, which revised the packaging and the accessory fittings of the Brisk line. Check the specifications table for the optical figures, since they stay the same across every configuration of the Brisk line.

What's in the box

• Optical tube with dust cap
• Four-vane spider and secondary mirror assembly
• 1.25 in 25 mm eyepiece
• 6x30 finder scope with bracket
• Laser collimator
• Equatorial mount with steel tripod
• Counterweight and counterweight shaft
• 25 mm and 10 mm eyepieces (1.25 in)
• 2x Barlow lens (1.25 in)

Compatibility notes

• Accepts 1.25 in eyepieces and filters directly in the focuser.
• The focuser travel supports a 2x Barlow lens for higher magnification.
• The tube mounts on basic alt-az mounts and small tabletop bases through a standard tripod-thread base.