Aurel Meridian 305 Dobsonian, with Dobsonian base

Specifications

Description

The Meridian 305 is a 12-inch Newtonian reflector with a 305 mm parabolic mirror and a 1,500 mm focal length, at f/4.9. It is designed for observers who want to see faint galaxies, small planetary nebulae, and globular clusters in detail.

A 305 mm mirror gathers about 19 times as much light as a 70 mm refractor and about 2.3 times as much as a 203 mm mirror. Under dark skies that opens up thousands of galaxies, including many in the NGC catalog that smaller telescopes show only as faint smudges. Bright galaxies such as M51 and M101 show spiral arms, and the Veil Nebula shows its filaments with a narrowband filter.

The tube uses a truss-free solid design with an internal light baffle, which keeps stray light out without a shroud. Three cooling fans move air across the primary mirror, and the mirror cell has tool-free collimation knobs. At f/4.9, collimation matters, so a laser collimator or a Cheshire tool is a good addition.

The 1,500 mm focal length reaches 250x with a 6 mm eyepiece. On nights of steady air, that shows fine detail on Jupiter and Saturn and splits close double stars. The 2 in dual-speed Crayford focuser handles heavy wide-field eyepieces and has a 10:1 fine-focus knob.

The tube weighs 21.5 kg and the base about 18 kg. Most people can carry each part a short distance, but stairs and long walks make a hand truck or a wheeled base worth considering. The eyepiece at the zenith sits about 1.5 m above the ground, which suits a standing adult or a tall observing chair.

About this configuration

Every configuration of the Aurel Meridian 305 Dobsonian shares the same optics; the choices below change how the telescope is mounted, finished, and equipped. A Dobsonian base needs no alignment, so you can set it on level ground and start observing within a few minutes. The base and the tube separate for transport, which makes the telescope easier to carry out of the house in two trips. The carbon fiber tube expands less as the temperature drops, so the focus point drifts less as the night cools.

A UHC filter from the deep-sky kit darkens the background sky around emission nebulae, especially under suburban light. This is the 2025 edition, which updated the knobs and clamps so you can operate them with gloves on cold nights. The optical figures in the specifications table apply to this configuration and to every other version of the Aurel Meridian 305 Dobsonian.

What's in the box

• Optical tube with 305 mm parabolic primary mirror
• Three primary mirror cooling fans with battery holder
• 8x50 right-angle correct-image finder with bracket
• 2 in to 1.25 in adapter
• Collimation cap
• Carry handles on the tube
• Dobsonian rocker base with altitude bearings
• 24 mm wide-field eyepiece (1.25 in)
• UHC nebula filter (1.25 in)

Compatibility notes

• Accepts 2 in and 1.25 in eyepieces, filters, and coma correctors.
• The tube fits the matching Dobsonian base; the tube-only version needs a large equatorial mount rated for at least 35 kg.
• Push-to encoders for 12-inch Dobsonian bases fit the altitude and azimuth bearings.