ASA Cassegrain- and Ritchey-Chrétien-Systems

(design by Philipp Keller).

Cassegrain and RC telescopes are used by professional observatories, research institutions and universities. The most famous telescope in the world, the hubble space telescope - uses the Ritchey–Chrétien (RC) design. The telescopes which ASA has on offer - a design by Astrooptik Philipp Keller - have since years been considered the reference class in the professional and semi-professional area. ASA is pleased to announce its cooperation with German physicist and optical engineer Philipp Keller to build and market these fine telescopes systems. The telescopes are made in open truss construction style with CFK-tubes and precision optics solely from Lomo Optics. Customers can choose to opt for the optical sets or the complete telescope system which can be set up in a equitorial or alt az design.

In combination with the reducer correctors and field flatteners designed by Philipp Keller, these instruments can also be used for large CCD sensors with diameters of 150mm and more and still display pin point stars all the way to the corners.

Spotdiagram

Apertures of 16, 20, and 24 inch are standard available models (Cassegrain f/9, RC f/8). All other apertures up to sizes of 1,5 meters (60 inches) are available on request.

DATASHEET

Best configuration possible: LOMO Optics inside!

LOMO Optics has established itself as a very reliable manufacturer of precision optics. Lomo also delivers optics for professional telescopes up to 2m in diameter. Lomo's mirrors are of the highest grade in the industry: If your aim is perfect imaging quality and you do not want to spend the few clear nights with inferior optics, then Lomo is the call. In order for the optics to provide optimal corrections also during volatile thermal conditions, we only offer our optical sets in either Astro Sitall or Zerodur ceramics. LOMO offers perfect quality parabolic mirrors, flat optics as well as Cassegrain- and RC-Systems. Contrary to other optic vendors we deliver every optical set with test certificate and Interferogramm. Philipp Keller has designed and implemented over 400 telescopes globally and all the optics delivered always more than have fulfilled his specification.

Cassegrain- and Ritchey-Chrétien-Systems

• System-wave front accuracy minimum L/8 Peak to Valley at 632 nm in focus
• System-wave front accuracy minimum L/35 RMS at 632 nm in focus
• Surface Quality 80/50 scratch/dig
• Coating Aluminium and Quartz, other coatings like silver and gold upon request!

Cassegrain and Ritchey-Chrétien design compared

Optical performance that will always perform on the seeing limit

Both the Ritchey-Chrétien and Cassegrain telescope will need a corrector when used with large format CCD cameras. When comparing the performance of both systems, the Cassegrain will perform very similar to the RC but at a lower price. The benefit of the RC-design lies in the fact that the smaller image errors are corrected easier. In building these systems, ASA Astrosysteme - unlike other manufactures in the field - focuses not on uncompromising lightweight construction, but on computer aided construction and company owned CNC-production. The result will be a more rigid system that will increase the precision of the telescope. Since professional telescopes are used in fixed locations, the slight gain of weight will be more than offset by the prevailing benefits such as higher pointing and tracking accuracy as well as improved focusing precision.

PERFECT IMAGING PERFORMANCE

ASA Cassegrain- and Ritchey-Chrétien-Systems

Best configuration possible: LOMO Optics inside!

Cassegrain- and Ritchey-Chrétien-Systems

Cassegrain and Ritchey-Chrétien design compared

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