Tessaro Obsidian EQ mount, with steel tripod

Specifications

Description

The Obsidian EQ mount is a manual German equatorial mount for refractors, catadioptric telescopes, and short reflectors with a combined load up to 4 kg. It turns on two axes that align with the celestial pole. Once the mount is polar aligned, motion in right ascension follows the stars across the sky, and you only need to adjust declination to move between objects. The head weighs 3.2 kg, so the mount suits a compact portable setup rather than a heavy observatory tube.

Polar alignment uses a built-in polar scope with an illuminated reticle. Set the latitude scale to your site's latitude, then aim the scope at Polaris and adjust the altitude and azimuth knobs until the reticle sits on the pole. Slow-motion cables on both axes let you center objects without touching the tube, which matters at high magnification, where a small hand movement can shift the target out of view.

An optional 12 V right ascension drive attaches to the polar axis and turns the mount at sidereal rate, so objects stay centered without manual correction. Without the drive, targets leave the field within a few minutes at high power. The drive draws about 0.5 A from a 12 V battery or regulated supply, and its rate can be adjusted with a small trim knob for lunar and solar work.

The Vixen-style saddle accepts dovetail bars up to 50 mm wide, and a safety screw holds the bar while you tighten the main clamp. The head has a standard 3/8-16 thread underneath for mounting on a photo tripod. Keep the total load, including the diagonal, eyepiece, finder, and any camera, well below the 4 kg rating. A longer tube shifts the balance point, so balance it on the saddle before you start tracking.

About this configuration

Each configuration of the Tessaro Obsidian EQ mount uses the same mount head; the options change what it stands on and what ships with it. The steel tripod gives a heavy, stable base that damps vibration quickly after you touch the focuser. A steel tripod adds weight to carry, but it settles fast when the wind picks up during a session. No add-on is included, which suits observers who already carry their own cases, bars, and power supplies.

A white mount head is easy to see in the dark, which helps you avoid walking into the tripod. The 2023 edition uses the same gears and bearings as later years, with small differences in the clamps. The payload rating in the specifications applies to the mount head in every configuration of the Obsidian line.

What's in the box

• Equatorial mount head with Vixen-style saddle
• Two slow-motion control cables
• Latitude scale and polar scope with illuminated reticle
• Accessory tray
• Steel tripod with accessory tray

Compatibility notes

• Accepts Vixen-style dovetail bars up to 50 mm wide.
• Suits refractors, catadioptrics, and short reflectors with a combined load up to 4 kg.
• The 3/8-16 base thread fits most photo tripods.