The Mewlon series of Dall-Kirkham Cassegrain telescopes from Takahashi offer the experienced observer a level of performance and portability not found in other Cassegrain telescopes. The classical Cassegrain telescope design offers excellent performance, but is extremely expensive to produce at large apertures. By concentrating on the Dall-Kirkham Cassegrains, the Takahashi Mewlon telescope offers a professional level of performance within reach of most amateurs.
The Takahashi Mewlon uses an ellipsoidal shape on the primary mirror and a spherical configuration on the secondary. By focusing on very tight tolerances for these surfaces, Takahashi is able to deliver a compact telescope with reasonable aperture and high resolution. Where fast f/ratios are not required, the f/12 Mewlons provide excellent contrast by utilizing a smaller secondary mirror than comparable Cassegrain designs. Secondary obstruction as a percentage of diameter is 29-31% on the Mewlons. Classical Cassegrain telescopes usually have secondary obstruction of 32% or greater. Commercial Schmidt-Cassegrains have secondary obstructions of approximately 38% for f/10 systems. Ritchey-Chretien Cassegrains have even more secondary obstruction making them less suitable for visual, high contrast applications.
Takahashi uses extensive knife-edge baffling to minimize stray light reflections as well as a specially designed tube that also acts as a light baffle. The result is an instrument that rivals an excellent long-focus Newtonian or refractor for contrast and sharpness. Some opticians have criticized the Dall-Kirkham design as having unacceptable coma. With most eyepieces (including Panoptics and Naglers) the coma is negligible and well outside the field of view. Stars are much smaller and sharper than in commercial Schmidt-Cassegrains. Coma may be a problem for wide-field astro-imaging, but these instruments were not designed for such tasks. With Takahashi's field flattener/reducer, these instruments offer superb off-axis images at f/9.
Takahashi produces precision optical surfaces capable of delivering a near perfect airy-disc heretofore unheard of in a production Cassegrain-design based instrument. Because the Mewlon primary mirror is larger than the effective aperture, its cell installation engineering helps to eliminate mirror stress which can cause astigmatism. The focuser mechanism has also been carefully designed to reduce shifting and maintain consistency. Focusing the M-210 is achieved by moving the primary mirror either farther from or closer to the secondary mirror cell by turning a silky smooth focusing knob on the optical back of the instrument.
Takahashi EM-200 Temma 2 "GoTo" Mount and Takahashi SE-L Mahogany Tripod are all INCLUDED in this PACKAGE
The EM-200 provides a stable support for all types of instrument (refractor, reflector or cassegrain) weighing up to 18kg. The modern aesthetic design of the EM-200 is highly attractive as well as beautifully functional. The RA and DEC stepper motors are fully integrated into the mounting, the high precision design and construction provides cyclic errors lower than +/- 5 arc seconds.
The integrated polar alignment telescope has an illuminated reticule which can be dimmed to suit the user or observing conditions. This in conjunction with the precision altitude and azimuth adjusters will typically give polar alignment accuracy within 2 minutes of arc of the celestial pole.
With a full function hand controller, options on tripods and piers makes the EM-200 an ideal mounting for the serious amateur.
700x Temma "Go To"now available at 12v. All "Go To" mounts are provided with RS232C cable, RJ-14 cable, shaft encoders and first quality stepper motors.The mount can operate in Temma mode and in the normal mode using the hand control. The Temma requires the use of a PC or Takahashi Advanced Temma Hand Controller to operate.
Name | Takahashi - Mewlon 210 Dall-Kirkham Telescope with EM-200 Mount |
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Manufacturer | Takahashi |
Model | TLS2145 |
Telescope Aperture | 8.1" - 10" |
Aperture | 210mm |
Finderscope | 7x50 6.3 degree |
Focal Length | 2415mm |
Focal Ratio | f/11.5 (f/9.3 with reducer) |
Limiting Stellar Magnitude | 13.4 |
Optical tube diameter | 244mm |
Optical Tube Length | 700mm |
Primary Mirror | 220mm F/2.9 |
Resolution | 0.55″ |
Secondary Mirror | 65mm /X4 |
Secondary Mirror Obstruction | 31% |