Celestron C90 Maksutov Cassegrain Spotting Scope

Celestron C90 Maksutov Cassegrain Spotting Scope

The Maksutov optical design is recognized for being a portable design that is easy to use and has a variety of applications, making it an excellent choice for both terrestrial and astronomical usage. This C90 Mak has excellent optics with razor sharp images over a wide field.

• Multi Coated Optics
• Maksutov-Cassegrain Optical Design
• Compact and Portable Design
• Erect Image System for Terrestrial and Astronomical Use
• Built-in T-Adapter threads for Ease of Adapting SLR Cameras
• Comes with 32 mm Eyepiece, 45° Erect Image Diagonal and 8x21 Erect Image Finderscope
• Backpack Made of Nylon
• Limited Lifetime Warranty

The Maksutov optical design is recognized for being a portable design that is easy to use and has a variety of applications, making it an excellent choice for both terrestrial and astronomical usage. This C90 Mak has excellent optics with razor sharp images over a wide field.

Maksutov-Cassegrain Optical Design

The MAK is a catadioptric spotting scope, which means the optical design includes both a lens and a mirror. The light coming through a MAK passes through the corrector lens to the primary mirror and back to a spherical secondary mirror before it hits the eyepiece. Images are bright, sharp, and virtually free of chromatic aberration. 

The Maksutov-Cassegrain’s optical design offers several unique benefits. Instead of a secondary mirror, the MAK features a “secondary spot” of reflective coating applied directly to the inside of the corrector plate. Because of this, the spotting scope does not require frequent collimation. Also, the secondary spot is significantly smaller, giving the MAK its signature high-contrast views.

One important thing to note about Maksutov-Cassegrain spotting scope is that the larger, heavier Maksutov corrector plate takes longer to cool down and adjust to ambient air temperature.