meade官网上的解释,,就是种慧差修正,,本质是RC折返
f/10 Advanced Coma-Free (ACF) Optics. Building from a classic RC design, Meade has created a new design with the same coma-free(慧差修正) pinpoint star images and flatter field also reduces the astigmatism(象散) and eliminates diffractions spikes found in classical RCs. The LX200-ACF is the perfect platform for the demanding researcher and imaging enthusiast with telescopes available in apertures of 8 inches, 10 inches, 12 inches, 14 inches, and 16 inches. |