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.
The optical system was designed to reduce more than just off-axis star coma, but also to give an astrograph quality flat focal plane all the way to the edge of the field of view.