Takahashi Mewlon-300 11.8" f/11.9 Dall-Kirkham Cassegrain

SOLD IN 2011


Dall-Kirkham Cassegrain telescopes are known for their image quality, and the Takahashi Mewlon 300 is no exception. The hand-figured optics of its Dall-Kirkham design use a concave ellipsoidal primary mirror and a convex spherical secondary mirror to produce a long f/11.9 focal ratio. Its images are essentially free from astigmatism, although at the expense of greater off-axis coma than a conventional reflector. While this limits its field of view, it provides exceptionally sharp images on-axis. The field is very dark, with pinpoint star images and an excellent contrast range. This makes the Dall-Kirkham design particularly well-suited to observations where exceptional resolving power is more important than a wide field of view, such as lunar and planetary observation and imaging, resolving compact globular clusters, etc.

The Mewlon’s 310mm primary mirror is oversized compared to the scope’s effective 300mm aperture for brighter off-axis images. The primary mirror is fixed and focusing is done electrically by moving the secondary mirror fore and aft in its holder under the control of a supplied battery-operated hand control. A variable length focusing tube makes quick work of changing between a visual focus and one for astrophotography.

An optional 0.8x reducer/field flattener/corrector lens (#TMC1800) is available for the Mewlon. It converts the 300 from a 3572mm focal length f/11.9 system to a 2739mm focal length f/9.1. This increases the image circle from 25mm at the focal plane at f/11.9 to 42mm at f/9.1 with the reducer in place. The field of view is 45 arc minutes using the reducer.

The well-made aluminum optical tube has die-cast and machined metal front and rear cells. The rear cell has removable cooling vents on the sides and a removable back for faster cooling of the optics. The rear cell has both 1.25" and 2" accessory holders; an illuminated 11 x 70mm finderscope in a double ring mount; and a dual split ring mounting designed specifically for installing the heavy Mewlon 300 optical tube on a Takahashi equatorial mount.

The Takahashi Mewlon 300 measures a substantial 43" in length, 12.75" in diameter, and weighs 57.2 pounds, requiring the use of a high payload capacity mount, such as the Takahashi EM-400 or EM-500.
  • Dall-Kirkham Telescope combines refractor-like performance in a larger folded optic reflector design.

  • The Takahashi Mewlon 300 at prime focus provides a focal length of 3572mm, focal ratio of f/11.9 and image circle of 25mm.

  • Primary mirror diameter measures 310mm (f/3) with a secondary mirror amplification of 95mm (4X) and secondary obstruction of 0.32 (29%).

  • The Takahashi Mewlon 300 measures 1094 mm long, 324 mm in diameter and weighs 57.2 lbs. (26kg).

  • It offers a limiting visual magnitude of 14.2 and a light grasp of 1836x - providing an outstanding resolution factor of .40 arc seconds.

  • The Takahashi Mewlon 300 with optional reducer can achieve a focal length of 2739mm, focal ratio of f/9.1, image circle of 42mm and a 45' image field.

  • Includes Tube Counterweight and Fraulhaber German Electric Focus Motor, 11X70 Finder and Double Finder Bracket.