Sky-Watcher Quantum top of the line ED-APO refractors offer premium optical performance for the discriminating amateur astronomer and imagers. Refractors are coveted for their high-definition, superb for optimal detail of planets and binary stars ...
APO Quality - Quantum refractors are designed to assure virtual elimination of residual chromatic aberration ("false color") normally present in 2-element achromatic lens designs. Using extra-low dispersion (ED) glass, S-FPL51, for two of the ...