Grand Eye Scientic Company

Takahashi© Cassegrain Reflector 高橋卡塞格林望遠鏡
CN-212 | BRC-250 | BRC-300 | C-300 | C-400

Takahashi© China


高橋中國

Telescope 望遠鏡
FS-60C | FS-78 | FS-102 | FS-128 | FS-152 | FSQ-106 | Sky-90
TOA-130 | FCT-150 | FCT-200 | FCT-250
μ-180 | μ-210 | μ-250 | μ-300
MT-130 | MT-160 | MT-200 | MT-250 | MT-300
ε-160 | ε-210 | ε-250 | ε-300 | ε-350
CN-212 | BRC-250 | BRC-300 | C-300 | C-400

Equatorial Mount 赤道儀
TG-SP 2 | Space Boy | P2-Z | EM-2S | EM-10USD3 | EM-200USD3 | NJP | EM-500
EM-10 Temma 2Jr | EM-200 Temma 2Jr | EM-200 Temma2 | NJP Temma2 | EM-500 Temma2
EM-2500 Temma-PC | EM-3500 Temma-PC

Accessory 附件 | Price List 價目表

Brief history of telescopes 望遠鏡簡史

Specification of telescopes at a glance 望遠鏡規格一覽

CN-212 Newtonian/Cassegrain telescope CN-212 牛頓/卡塞格林望遠鏡

The idea of combining the advantages of Cassegrain and Newtonian configurations in one instrument has been around for a long time but with very few examples commercially available.

Thus it was not so much a novelty of telescope optics , but rather the result of a long held need for the ideal all-round telescope for the amateur use that gave birth to the Takahashi CN-212.

The optical principle of the CN-212 is simple yet clever. From a primary short focus parabolic mirror, pierced centrally, different optical configurations are possible depending on the secondary mirror placed in the light cone. Here we have two telescopes in one, an f/12.4 Cassegrain as the basic configuration, with a hyperbolic secondary mirror for high resolution work, or when you require, by simply replacing the secondary mirror and coupled with a low profile 2" eyepeice adaptor and associated field corrector, you transform your instrument into a brilliant wide field Newtonian with a focal ratio of f/3.9　

Specification of CN-212

Effective Aperture	212mm	212mm
Focal Length	2630mm	820mm
Focal Ratio	F12.4	F3.9
Diameter of secondary	Ø68mm
Diameter of diagonal		Ø72mm
Resolution	0.55"	0.55"
Light gathering power	917x	917x
Limiting magnitude	13.4	13.4
Image Circle	36	43
Photographic field	0.8°	2.9°
Finder scope	7x50 6.3°	7x50 6.3°
Length of main tube	855mm	855mm
Weight of main tube	8.5kg (18.7lbs)	8.5kg(18.7lbs)

CN-212 Cassegrain Focus System Chart

4. Locking screw
6. 50.8mm adapter
7. Locking ring
14. Coupling (L)
18. Reducer
19. Reducer (Mewlon)
24. Diagonal Prism (L)
29. 5-turret w/DP (L)
31. TSC Prime focus ring
32. T-mount
33. Wide T-mount
34. 35mm SLR camera
36. TCA-4 camera adapter
45. Couplin, DP (L)
46. Adapter 31.7mm oculars
47. Oculars (31.7mm)
48. Oculars (2")
49. Diagonal prism (M)
60. Vari-Extender
61. Vari-tube
75. CCD camera
80. 50.8mm sleeve (easy guider)
81. Easy guider (Lumicon)
90. Twin View

CN-212 Newtonain Focus System Chart

38. ø82mm filter
70. Newtonian visual back (for Lumicon)
71. Newtonian extension tube (for
Lumicon)
72. Flattener

　
BRC-250 Baker Ritchey-Chretien

The BRC-250 employs non-spherical surfaces for both the primary and secondary mirrors, and when they are combined with two supplementary lenses, eliminates spherical aberration, coma, and even astigmatism with a flat field. It produces a focal ratio of f/5 with a 100mm 5? image circle. It also produces an amazing 2 micron stellar image at the center of the field.

The BRC-250 employs the Baker method to Flatten the field over a wide field. However, because its primary and secondary mirrors are hyperbolic, production was difficult. Today, Takahashi's unique technique in polishing non-spherical surfaces enables the first mass production of Baker Richie Chretiens.

　

Takahashi C-400 Observatory

The C-400 16" f/14 Classical Cassegrain is part of Takahashi's Observatory Series telescopes designed primarily for research and educational institutions. This telescope comes standard with a removable f/10.4 focal reducer where a wider field of view is required. Because the C-400 employs the Classical Cassegrainian configuration with a parabolic primary mirror and hyperbolic secondary, extremely high resolution can be obtained without sacrificing contrast or a flat field.
Secondary obstruction is only 29% with this instrument as compared to 40% or greater with typical Ritchey-Chretien Cassegrains. As with the FCT-200 and FCT-250 Observatory fluorite refractors, this instrument is designed for rigorous research applications and is constructed with meticulous craftsmanship throughout. The optical tube assembly weighs 165lbs. so a heavy-duty, permanent equatorial mount with high-precision Go-To slewing such as Takahashi's Temma EM-2500 or EM-3500 (illustrated) is recommended for most applications.
Since this is a custom made telescope, each instrument is made to order and delivery times may vary.

　　
BRC-250 望遠鏡: 參考標準望遠鏡

Specification for

F0

T

　

Specification for FCT-200