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| Télescopes astronomiques / Telescopes for astronomy | Catadioptriques / Catadioptrics |
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PRO RC 250 CLOSED OTA
The Pro RC Series Ritchey Chrétien telescopes made by Officina Stellare are built around the best quality optics available today.
All optical sets are realized under precise quality requirement conditions, using the highest renewed standards in terms of quality of the materials being used and the production processes involved.
Each optical set is provided with its own interferometry report stating and certifying the overall quality to the customer. In the making of the optics, Officina Stellare only uses blanks of certified origin and perfect homogeneity. They offer, as a standard, very high reflectivity protected aluminizings and multi-layer anti-reflexion coatings. Each and every one of our instruments is verified by Officina Stellare before delivery to the final user.
The advantages of the original Ritchey Chrétien (RC) optical scheme are very well known since their introduction. It's the most diffused optical scheme, adopted by professionals all over the world. The Hubble space telescope itself uses the RC configuration. It is a peculiar variation of the more classical Cassegrain scheme that uses only two hyperbolic shaped mir-rors. The use of this aspherical curvature shape, very difficult to achieve, results in a very efficient optical system, particularly suited for astrophotogra-phy and professional use.
The use of only two optical surfaces guarantees the minimum possible light loss and the resulting telescope is “aplanatic” which means coma free (the coma is one of the most known off axis optical abberations that greatly degrades the quality of the images and probably the most annoying one). The resulting stellar images are particu-larly well corrected along the entire illuminated field and the small residual field curvature (particularly low, thanks to the small multiplier factor of the secondary mirror which is typically half the factor of the common Schmidt-Cassegrain tele-scopes) is easily corrected using custom designed corrector lenses.
Sometimes just one lens is enough, and the flatteners are only needed with the use of very large CCD sensors. Many users operate the telescopes for imaging without the use of such correctors. This is obtained with the perfect coupling between the field of view , the pixel size and the focal length in respect
to the medium viewing conditions.
In such a case, a very well corrected and just reflective telescope is more flexible in terms of use, allowing the user to op-erate in a more wide range of spectral frequency without having any chromatic aberration issues. This particular aspect of the telescope is sometimes determinant in the final decision for particular research fields.
Model: Pro RC 250 LC
Type : Ritchey Chrétien
Clear Ø : 250 mm
OTA assembly type : Carbon close tube / CNC aluminium
Focal lenth : 2000 mm
F / ratio : F/8
Optical set glass : LK7
Interferometric report : Yes
Weight : 13 / 17 Kg
Overall OTA length : 690 mm
Overall OTA Ø : 330 / 340 mm
Spot size (@26 mm from axis, w/flattener) 15 microns
Standard configuration : Zero Expansion close carbon tube design, unique ed innovative primary cell design, two removable Losmandy type dovetails, primary mirror three fans ventilation. | OSPRC250COTA
13618.95 CAN$ | |
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