Officina Stellare Veloce Astrograph
The materials Officinia Stellare uses in their premium quality telescopes are mostly aluminum and carbon fiber because of their lightness, their mechanical and thermal properties and for the optimal resistance to environmental conditions.
All the mechanical parts for the the Veloce OTA Astrograph are constructed with CNC computer assisted machines and from a whole aluminum blocks to guarantee the best possible precision. In addition, Officina Stellare has also provided carbon fiber components that are produced with strict specification and tolerances. Each section of this astrograph has been computer designed and simulated and optimized for the best structural performance, rigidity and lightness. The Veloce Astrograph's holding systems for the mirrors, the spider, rings and all the structural components, even the smallest, are CNC machined from a single block of special aluminum (6061/7075, Ergal and Anticorodal), stainless steel, titanium and brass. The astrograph's tubes are equipped with true carbon-graphite fiber obtained with the use of high vacuum process, allowing you as the observor to obtain the remarkable stability of the focus vs temperature changes and yet still maintain excellent and superior structural rigidity and lightness.
Officina Stellare is providing excellent care is constructing the rear holding cell of the Veloce astrograph's primary mirror. The rear cell for the primary mirror is figured to have the best rigidity/weight ratio and for the fastest possible thermal stabilization between the environment and mirror. The convection and thermal irradiation are greatly improved with the use of three high quality axial fans in the back of the astrograph's cell.
Officina Stellare has focused on simplifying the collimation between the Veloce astrograph's mirrors to resulting in a stable, efficient but easy to use system. Collimation is achieved on three points (the minimum required points to generate a single plane) that use special, great diameter preloaded bolts (one for each point). This results in a single hand use, simply turn the bolt left or right to move the mirror back and forth (no more complicated operations using push pull screws and locks) in a very intuitive way. Officina Stellare has made this one step easier! Finding the correct positions is a snap. The borders of the mirrors use an opaque, circular mask to avoid any undesired light scattering which always aids in the astrophotography experience. The light shields for both the primary and secondary mirrors on the Veloce are computer blueprinted and optimized to ensure illumination of the field is complete while still maintaining a complete protection from stray light. Inside the light shields there are also micro baffles that reduces, coupled with an opaque painting of the surfaces, to nearly zero any possible parasite stray light. In some cases and for particular applications, the light shield for the secondary mirror in the astrograph is made using a unique design to enable efficiency of the telescope while reducing the obstruction for the system. The back plate of Officina Stellare's telescopes comes standard with a system for adjusting the planarity of the focal plane in order to compensate for any small misalignment in the imaging train, always unwanted and annoying specially on today’s large CCD cameras.
The ultra fast Riccardi-Honders astrograph represents the only true innovation in optics of the past fewyears.Born from the intuition of the Italian designer Dr. Massimo Riccardi, as a variant of the original Hondersdesign, this new configuration achieved the purpose of combining the extremely fast F/3 focal ratio with aflat, very large diameter, imaging field.In addition to these amazing optical performances, the Veloce RH Series instruments are distinguished byan impressive compactness, unique in its kind, making them very easy to transport and easy to install ontypical amateur mounts.The Veloce RH series produced by Officina Stellare are the only instruments in the world designed personally by Dr. Riccardi, inventor of the Riccardi-Honders optical design.The Veloce Series of telescopes are theperfect instruments for those astroimagerswho are searching for a very large,corrected, field. Large nebulas or starsfield will be deeply reproduced withvery high resolution and full details. Thevery fast focal ratio allows for the use ofvery narrow band filters keeping shortthe exposure times, and the widest possibleimaging field greatly facilitates therealization of variable stars, asteroids orextrasolar planet search surveys.
The back surface reflection of the primary mirror (called Mangin) is the main characteristic distinguishing the Riccardi-Honders optical design. Combining the reflecting and double refracting action (the incoming light passes twicethrough the full thickness of the primary mirror) of this element it is possible to obtain a greater optical correction while maintaining the instrument extremely compact.The optical design includes a full aperture corrector plate and it is completedwith a two element flattener group situated before the focal plane. This complexoptical system guarantees to the astroimager a greater off-axis correctioneven with a very fast F/3 focal ratio.Another important factor is that the Riccardi-Honders optical design contemplatesspherical surfaces, this results in the advantage of greater ease ofcollimation and in its stability over the long term.
Thanks to the most recent optical design software which allows to verify the focus shift caused by ambient temperature variations, it was possible to identify and produce the mechanical components optimized to allow for thermal compensation of these variations. This guarantees a stable focal position during imaging sessions, an essential condition when using instruments with such a fast focal ratio.All the mechanical parts are produced using only the finest materials available, such as special lightweight aluminum/Ergal, stainless steel, bronze and particular alloys for thermal compensation. The tube is designed and optimized with CAD and computer support modelling to achieve the best rigidity and lightness. All parts are full CNC machined to guarantee the best possible precision.The high resistance anodization is chosen for unbeatable resistance to environmental conditions.The Veloce Series can also mount a piggy back support specially designed by Officina Stellare for a stand alone autoguider.Finally, the great mechanical extraction of focal plane position allows to use complex imaging trains, both with CCD or the more popular digital reflex cameras.
Statement from Dennis di Cicco
I tested the astrograph with a Nikon D700 full-frame DSLR; an FLI ProLine 16803 CCD camera, and the new SBIG STT-8300 CCD camera pictured on page 61 (which will be reviewed in an upcoming issue). Officina Stellare provided me with adapters for the Nikon and FLI cameras, and, because of its newness, I machined my own adapter for the STT-8300. However, I’m sure these will become commercially available very quickly. Although it’s possible to use standard T-thread adapters to mount DSLRs to the RH200, these are only suitable for cameras with APS-size chips. Using full-frame cameras with T adapters will vignette the corners of the frame due to the restricted clear aperture of T-thread fittings. There are several sources, including Borg and Teleskop-Service, that offer large-aperture adapters made specifically for astrophotography with full-frame DSLR cameras.
|Name||Officina Stellare - Veloce RH 200 Riccardi-Honders Astrograph Optical Tube Assembly|
|Focal Length||600 mm|
|Optical Design||Riccardi-Honders Astrograph|
|Optical Tube||Auto-thermal comp with BK7 glass|
|Optical Tube Length||235 mm|