Apertura 6” f/9 Ritchey-Chretien OTA

Please Note:  This OTA is recommended for photographic applications only.  While you can add a diagonal and eyepiece, the results will not great. Thanks.

Ritchey-Chretien telescopes are used in some of the world’s biggest and best observatories due to their color-free, coma-free, spherical aberration-free optics. However, Ritchey-Chretien telescopes are often out of the reach of most backyard astro-imagers due to their high price tag. However, Apertura is delivering that great Ritchey-Chretien performance to you in an OTA that won't break the bank!

This Apertura RC telescope has 6” of aperture and a focal ratio of f/9. The 6" Ritchey-Chretien's primary & secondary mirrors are made of BK7 glass and coated in aluminum with a 96% reflective surface. The aluminum is then overcoated with quartz. This high reflectivity coating offers higher contrast images and protection against scratching.

Inside the 6” Apertura RC telescope is a Knife-Edge Baffle System whose only job is to keep stray light out of the telescope’s interior. The addition of a dew shield (sold separately) would help further defeat stray light, so we recommend picking one up. The OTA mounts easily to a variety of mounts that accept Vixen-style dovetails. Simply remove the dovetail if you choose to mount the telescope via cradle rings.

A high-quality 2” dual speed Crayford focuser comes standard with the Apertura 6” f/9 Ritchey, and you'll also get a 2" to 1.25" adapter as well as a 2" long thread-on extension and two (2) 1" long thread-on extensions. One thing that really sets this 6" Ritchey-Chretien telescope apart from Schmidt-Cassegrains, even though it looks like one, is the lack of image shift. In SCT’s, the focuser moves the mirror forward and back on a rail, and it is this movement that can cause image shift. The mirror of the Apertura 6” RC is fixed into place, similar to that of a Newtonian. It is not connected to the focuser in any way. Removing this connection removes image shift. To collimate the RC, adjustments are made to the secondary mirror.

Apertura 6” f/9 RC Telescope OTA Specifications

• Optical Design: Ritchey-Chretien

• Aperture: 6”

• Focal Length: 1370 mm

• Focal Ratio: f/9

• Mirror Material: BK7 Glass

• Coatings: 96% aluminum with quartz overcoat

• Optical Tube Material: Metal

• OTA Length: 19.1”

• OTA Weight: 12.3 lb.

Included in the Box

• 6" f/9 Ritchey-Chretien OTA - Steel Tube

• 2" Dual-Speed Crayford Focuser

• 2" to 1.25" Adapter

• Vixen-Style Dovetail

• 2" Long Thread-On Extension

• Two 1" Long Thread-On Extensions

• Finderscope Base