Takahashi's Dall-Kirkham "Mewlon" series reflectors are long focal length telescopes with high F/D focal ratio. The primary mirror is ellipsoidal while the secondary mirror is spherical. The surface accuracy of the optics is at least λ/20.
The CRS models incorporate a field corrector with ED glass lenses that provides a F/10 focal ratio along with a larger, more corrected field thus converting the telescope into a flat-field instrument for imaging and visual observation. In addition, the CRS series has an electronic focusing system controllable with an ASCOM driver or in an autofocus mode. Each CRS telescope features a primary mirror cooled by 3 fans.
The motorized focusing, ASCOM compatible, is done by translating the secondary mirror. The fans responsible for heating the primary mirror are managed by 3 temperature sensors located inside and outside the tube.
The Mewlon-250CRS is perfectly suited for planetary observation and imaging, due to its long focal length. It is also ideal for deep sky applications; equipped with the F/7.3 reducer it will allow the imaging of compact objects such as planetary nebulae or galaxies. The integrated 7x50 finder scope is adjustable and serves as a handle for transport.
The optical tube assembly is delivered with a pair of rings connected by a massive plate located under the tube.
| CHARACTERISTIC | TAKAHASHI MEWLON-250CRS REFLECTOR |
| Optical design | Modified Dall-Kirkham |
| Combination | Concave elliptical primary mirror + convex spherical secondary mirror + field corrector |
| Diameter | 250 mm |
| AT PRIME FOCUS | |
| Focal length | 2500 mm |
| Focal ratio | F/10 |
| Image circle diameter | 40 mm |
| Metal Back Distance | 147.9 mm |
| WITH RD CR0.73X FOCAL REDUCER | |
| Focal length | 1825 mm |
| Focal ratio | F/7.3 |
| Image circle diameter | 35 mm |
| Metal Back Distance | 72.2 mm |
| WITH EX CR1.5X FOCAL EXTENDER | |
| Focal length | 3780 mm |
| Focal ratio | F/15.1 |
| Image circle diameter | 44 mm |
| Metal Back Distance | 117.5 mm |
| CHARACTERISTIC | TAKAHASHI MEWLON-250CRS REFLECTOR |
| Length of the optical tube assembly | 945 mm |
| Diameter of the optical tube assembly | 280 mm |
| Weight | 12 kg |
Spot-diagram of Takahashi Mewlon-250CRS reflector at prime focus
Spot-diagram of Takahashi Mewlon-250CRS reflector with RD CR0.73X focal reducer
Please note: mount, tripod, and tube holder sold separately.
Included in the box:
Optical Tube Assembly (w/finder)
M92-72 Coupling TKP84111
50.8 (2") Sleeve TKP00113
Coupling (S) TKP00103
Aux. Ring (prime focus) TKP83002
Ocular adapter (31.7) TKP00101
Ocular adapter (50.8) TKP82110
Extension tube (50.8) TKP31112
System Charts
Mewlon 250CRS System Chart with 1.5X Extender
Recommended for the TAKAHASHI CORRECTED MEWLON-250CRS
Product title
Vendor
$19.99 | $24.99
Product title
Vendor
$19.99 | $24.99
Product title
Vendor
$19.99 | $24.99
Product title
Vendor