Telescope Officina Stellare Ultra CRC 250 FULL version

INFORMATIVE NOTE: on the prices indicated for each of the OFFICINA STELLARE telescopes we will have to add the costs derived from the transport boxes, since the packaging is critical in this type of high-end product to avoid any damage in the transport from origin to destination. Therefore, once you know which model you are interested in, please contact us to define the cost of transport packaging as well as to see recommended accessories for it.

FULL version: OTA version with Fli ATLAS focuser, customized CCD camera adapter.

Ultra CRC from Officina Stellare: the road to perfection

The Ultra CRC series represents a new reference in the ultra-fast astrograph market.
Thanks to its 4 elements (Ultra Corrected Ritchey-Chrétien hyperbolic optical system, exclusive to Officina Stellare), the Ultra CRC represents an ideal solution for astrophotographers looking for fast, large diameter, field corrected instruments to cover end-to-end the field captured by the largest CCD on the market.
Developed to offer the highest performance in photography, while keeping light weight and compact optical tubes in mind, the Ultra CRC telescopes are the evolution to a larger field of capture of the previously existing traditional Ritchey-Chrétien telescopes.

Optics

Ultra CRC is the acronym for Ultra Corrected Ritchey-Chrétien (Ultra Corrected Ritchey-Chrétien), an innovative and exclusive design of Officina Stellare, with 4 elements, a fast focal ratio and flat field (no field curvature), which represents the latest of the pioneering projects that Officina Stellare has been carrying out in recent times. Developed to provide the highest performance desirable in astrophotography, while maintaining high efficiency in transferring light to the focal plane, the system consists of only two hyperbolic mirrors and a 2-element group located at the rear of the tube for field correction.
In keeping with the quality of the telescope, the mirrors are made of Sitall ceramic glass with a near-zero coefficient of thermal expansion or LK7 glass.
The illuminated and corrected field covers a diameter of 60mm, with great performance with stars of less than 5 microns (RMS 1 micron) at 30mm from the optical axis, obtained at a focal ratio of F/5.4.

Mechanics

The reduced focal ratio of the Ultra CRC astrographs allows to keep the weight and the total volume of the optical tube in quite moderate values.
The novel "dual-phase" hood on the secondary mirror is optimized via software to prevent it from being too heavy and to minimize obstruction, thus increasing the amount of light reaching the focal plane.

The carbon fiber and aluminum structure of OFFICINA STELLARE's Ultra CRC telescopes has been designed and optimized with CAD and modeling software support to achieve the highest rigidity and lightness. The optical configuration designed using a vacuum production process, high quality carbon fiber tubes and zero coefficient of expansion ensures high focusing stability. Only ultra-light aluminum/Ergal alloys, stainless steel and bronze have been used in its manufacture. All parts are CNC machined to ensure maximum precision.

The high-strength anodized finish has been selected for its resistance to harsh environmental conditions. Our unique and innovative cell support design of the primary (axial/radial multipoint) as well as the secondary cell guarantees absolutely no induced astigmatism in the mirrors and the absence of mirror displacements.

Because the OFFICINA STELLARE Ultra CRC telescopes feature a robust, efficient and user-friendly collimation system (single motion operation), achieving perfect collimation has become an extremely simple and immediate process.

The Ultra CRC offers the astrophotographer great focal plane extraction. This guarantees the possibility to install complex optical trains, coupling CCD cameras, off-axis guiding systems, adaptive optics, filter wheels, etc., as it has to be for such complete optical systems.

Thanks to the mechanical design and the presence of three high quality fans, thermal stabilization is achieved in the shortest possible time. The mechanical design includes as standard 4 dovetails type Losmandy on the sides to attach to the mount and to place piggyback guide tubes.

Great attention to detail has gone into the construction of such an astronomical telescope:

- Computer design
- Focal plane tilt adjustment
- High precision spherical joint for the truss structure
- Parallel double divider ring for the secondary mirror/spider holder
- Radial micrometer adjustment of the spider
- Manual or motorized movement of the secondary mirror without the possibility of shifting
- Special opaque painting for all sensitive parts of the optical path

Technical specifications

- Free diameter: 250mm (9.8")
- Focal length: 1400mm
- Focal ratio: F/5.6
- Glass used: LK7 or Sitall
- Frame type: Carbon fiber truss
- Weight: 17Kg
- Length: 580mm
- Tube diameter: 400mm
- RGB Spot size: 2.4mn (RMS)
- Backfocus length (useful): 250mm (220mm)
- Linear obscuration: 48% - Backfocus length (useful): 250mm (220mm) - Linear obstruction: 48% - Backfocus length (useful): 250mm (220mm)