The Veloce RH250-AT is unique in the Veloce lineup. Originally designed for a scientific project, the RH250's performance was so good that Officina Stellare decided to put it into full production. Unlike the other Veloce telescopes which are f/3, the RH250 is f/5.6. While it is a little slower, the RMS spot size at the edge of the field (not just on-axis) is an astounding 3.6 microns, making this one of the sharpest compact imaging scopes available.
The ultra fast Riccardi-Honders astrograph represents the only true innovation in optics in the past few years. Born from the intuition of Italian designer Dr. Massimo Riccardi, as a variant of the original Honders design, this new configuration combines extremely fast focal ratios with a flat imaging field and a very large diameter. In addition to this amazing optical performance, the Veloce RH Series instruments are distinguished by an impressive compactness, unique in its kind, making it very easy to transport and easy to install on typical amateur mounts. The Veloce series of telescopes are the perfect instruments for those astroimagers who are searching for a very large corrected field.
The very fast focal ratio allows for the use of very narrow band filters, keeping exposure times short, while the widest possible imaging field greatly facilitates the realization of variable stars, asteroids or extra-solar 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 through the full thickness of the primary mirror twice) of this element, it is possible to obtain a greater optical correction while maintaining the instrument extremely compact. The optical design includes a lens and a two element flattener group situated before the focal plane. This complex optical system guarantees the astroimager a greater off-axis correction, even with a fast F/5.6 focal ratio.
Getting closer to perfection, the Veloce now uses an innovative Nano Coating® which has an amazing resistance to dust and moisture and a better transmission over a wider wavelength bandwidth range, a feature appreciated by professionals.
An interesting fact about the RH Veloce: since the double frontal lens is convergent, the Mangin mirror is smaller than the "nominal" diameter of the scope, while the meniscus itself is bigger than the nominal diameter, ensuring a good illumination over the wide field of view of such scopes. For example, the 200mm model has a 220mm meniscus and a 190mm primary mirror. The secondary mirror is a separated piece of glass, or it is made coating the middle of the meniscus depending on the model. For this reason, "entry pupil" is mentioned and not "primary mirror diameter" for these instruments.
Due to the most recent optical and mechanical design software used during the latest development, the Veloce Series has a fixed focal position versus temperature shift during imaging sessions, an essential condition when using instruments with such a fast focal ratio. All the mechanical parts are produced using the finest materials available only, such as special lightweight aluminum/Ergal, stainless steel and bronze. 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. Finally, the good extraction of focal plane position allows to use complex imaging trains, both with CCD, CMOS or the more popular digital reflex cameras.
|Optical design||Riccardi-Honders, flat-field|
|Entry pupil||250 mm|
|Primary mirror diameter
|Front corrector lens diameter
|Fully corrected and
|Dimensions (mm)||630 (with dew shield) L x 318 Ø|
|Backfocus from back plate||200 mm|
|RMS polychromatic spot size||Max. 3.6 microns at field edge|