The VMC200L is a unique catadioptric optical system. It incorporates a primary mirror and a meniscus corrector just before a secondary mirror. By doing so, light is corrected twice on the optical path. The end result is that spherical aberration and field curvature are corrected to a high degree of optical performance. The VMC200L’s primary mirror is f/2.5; the compound optical system is f/9.75. This makes the system much more compact and portable than its competition. With the optical correction placed before the secondary mirror, the VMC200L avoids the necessity of having a corrector plate and all the dewing problems associated with a closed optical tube.