Corvane Trestle alt-az mount, head only

Specifications

Description

The Trestle is a manual alt-azimuth mount for telescopes and spotting scopes up to 12 kg. It moves in altitude, up and down, and in azimuth, side to side, so you point it the way you would aim a pair of binoculars: put the target in view and the mount follows your hand. The twin columns share the load evenly, which keeps the head steady when a heavier tube is attached.

Slow-motion rods on both axes let you make fine corrections without touching the tube. Those rods matter most at high magnification, where an object drifts out of the field within a minute or two and a touch by hand would shake the image. Tension knobs on each axis set how freely the head turns, so you can run it loose for sweeping across the sky or firm for small adjustments.

The dovetail saddle is 200 mm long and accepts most bars sold with telescopes in the 80 to 150 mm aperture range. A locking screw on the front clamp holds the bar in place while you tighten the main clamp. The head weighs 7.6 kg and has a 3/8-16 thread underneath for a tripod or pier adapter. Use a sturdy tripod, because the head mass and the load together put considerable demand on the legs.

Keep the total load well below the 12 kg rating. That figure includes the tube, diagonal, eyepieces, finder, and any camera. Long-focus tubes take longer to settle after focusing, and the slow-motion rods work best once the head has stopped moving.

The Trestle has no motors and does not track the sky. For visual observing at low and medium power, manual tracking with the rods is enough for most sessions. It suits a permanent pier or a rooftop deck where the setup stays in place, and it pairs well with a larger refractor or a Newtonian reflector.

About this configuration

The Corvane Trestle alt-az mount is sold in several configurations, and the notes below describe what this particular one includes. This configuration is the mount head alone, so you supply a tripod or a pier with a matching top plate. Buying the head only makes sense when you already own a sturdy tripod or a permanent pier in the garden. A padded case makes it easier to carry the mount head to a dark site without knocks to the axes.

The white finish stays cooler in sunshine, which helps if you set up the mount in the afternoon. The mechanics of the 2024 edition match the other years; the changes concern handling details only. The payload rating in the specifications applies to the mount head in every configuration of the Trestle line.

What's in the box

• Alt-az mount head with dovetail saddle
• Two slow-motion control rods
• Tension adjustment knobs
• Accessory tray
• Tripod adapter, 3/8-16 to 1/4-20
• Padded carrying case

Compatibility notes

• The saddle accepts dovetail bars up to 200 mm long, secured by a locking screw on the front clamp.
• The 3/8-16 base thread fits most photo tripods; a 1/4-20 adapter is included.
• Suits telescopes up to about 150 mm aperture and a total load of 12 kg.