This Meade Advanced Coma-Free 8” f/10 LX200 Optical Tube comes with diffraction-limited optics that consist of an over-sized Low-Expansion Borosilicate Primary Mirror, a Schott Borofloat Glass Corrector Plate, and Meade’s famous Ultra-High Transmission Coatings.
The Meade Advanced Coma-Free (ACF) optical system has brought the highest level of optical performance well within the reach of most amateurs. Using Meade’s exclusive design, ACF optics achieve aplanatic performance — with a flatter field, reduced astigmatism and eliminated diffractions spikes equal to Ritchey-Chrétien systems, at a fraction of the price.
The 8” f/10 ACF Optical Tube Assembly also features a primary mirror locking mechanism, which effectively prevents movement of the primary mirror during long exposure astrophotography or observing. Turn the lock knob located just above the telescope’s main focus knob and the progressive-tension primary lock completely cancels any residual image shift due to mirror movement during visual, photographic, or imaging applications.