Konus's MotorMax-90 90mm f/13.3 Maksutov-Cassegrain Telescope employs a front convex meniscus lens that not only eliminates the need for periodic collimation, but also requires a smaller secondary mirror when compared to a Schmidt-Cassegrain design. The Mak-Cass optical path results in a slower focal ratio and narrower field of view versus a similar Schmidt, but the optical benefits make this an ideal scope for planetary and double-star observation.
The scope is outfitted with a German equatorial mount and features a Right Ascension (RA) motor to track objects during extended observation sessions. To make manual adjustments, there are also RA and declination cables. Utilizing the RA motor not only frees you to concentrate on observation, it also greatly reduces vibration—especially at higher magnifications—for clearer viewing.
An internal flip mirror redirects the light path from the eyepiece holder on top of the optical tube assembly to the visual back, and for more comfortable viewing a 45° star diagonal is also included. The scope comes with two eyepieces that produce 70x and 120x power as well as a Moon filter to safely observe the Moon.
- 3.5" (90mm) aperture
- f/13.3 focal ratio
- 1200mm focal length
- Compact Maksutov-Cassegrain optical design
- Front convex meniscus lens helps to correct for spherical aberration for reduced distortion at the edges of the field of view
- Anti-reflection multi-coated optics reduce light loss and increase contrast and image brightness
- Internal flip mirror directs optical path from visual back to upper 90° eyepiece holder
- German equatorial mount
- RA tracking motor, runs on one 9V battery
- Manual RA and declination slow-motion cables
- Bar and counterweight for proper balancing
- Aluminum two-stage tripod, adjusts from 29 to 48" high
- 10mm focal length, 1.25"-diameter barrel eyepiece: 120x power
- 17mm focal length, 1.25"-diameter barrel eyepiece: 70x power
- 45° star diagonal, 1.25" barrel, for viewing through the visual back
- Moon filter for safe observation, especially during full phases
- 8x21 straight-view finderscope
- Smartphone holder