Halden Anvil 254 Newtonian reflector, tube with alt-az mount

Specifications

Description

The Anvil 254 is a Newtonian reflector built around a 254 mm parabolic primary mirror with 1143 mm of focal length. At f/4.5, it gathers light quickly and produces a wide field at low power, which suits large nebulae, rich star clouds, and extended open clusters. The same optics also reach high magnification on the Moon and planets when paired with shorter-focal-length eyepieces.

The primary mirror is figured to a parabolic curve and coated with aluminum and a protective overcoat. Because the optical path contains no lenses, the telescope shows no chromatic aberration, and the image stays free of color fringes around bright planets and the lunar limb. The primary mirror sits in a cell with three collimation screws, and the secondary mirror is held by a four-vane spider. Check collimation before each session, since small misalignments reduce contrast on planetary detail and on close double stars. The 2 in focuser holds a heavy eyepiece steady, and its fine-focus knob allows smooth adjustment at high power.

At 14.8 kg for the tube, the Anvil 254 is suited to a Dobsonian base or to an equatorial mount rated for at least 20 kg of payload. The mirror holds heat and takes time to match outdoor air temperature, so plan on setting the telescope outside 45 to 60 minutes before observing. Typical targets include the Orion Nebula, the Andromeda Galaxy, and the Hercules Globular Cluster, which resolves into individual stars under dark skies. Jupiter's cloud belts and the Cassini Division in Saturn's rings are visible on steady nights at high power.

About this configuration

The Halden Anvil 254 Newtonian reflector is offered in several configurations, and the notes below describe what this particular combination adds or changes. An alt-az mount keeps setup short: level the tripod, attach the tube, align the finder, and start finding targets. Manual alt-az motion suits visual observing, though you need to nudge the tube now and then to follow objects as the sky turns. The carbon fiber tube expands less as the temperature drops, so the focus point drifts less as the night cools.

The planetary kit adds a short focal length eyepiece and a set of color filters for the Moon and the bright planets. This is the 2023 edition of the Anvil line, the earliest version that is still listed in the catalog. If you plan to add accessories later, compare the compatibility notes with the parts you already own before choosing a configuration.

What's in the box

• Optical tube assembly with 254 mm primary mirror
• Secondary mirror with four-vane spider
• 8x50 finderscope with bracket
• 2 in focuser with 1.25 in eyepiece adapter
• Collimation tool
• Front and rear dust caps
• Alt-az mount with aluminum tripod
• 6 mm planetary eyepiece (1.25 in)
• Four color filters (1.25 in)

Compatibility notes

• Accepts 2 in eyepieces directly and 1.25 in eyepieces through the supplied adapter.
• Mounts on a Dobsonian base or an equatorial mount rated for at least 20 kg of payload.
• The tube has no dovetail bar, so mount it with a rocker box or a compatible tube-ring system.