Since they first hit the U.S. market some 10 years ago, Sky-Watcher USA telescopes have become synonymous with great value. Whether you’re talking about refractors or reflectors, these high-quality instruments promise real bang for your observing buck.
Sky-Watcher USA offers three instruments in their line of ProED Doublet APO Refractors, with apertures of 3.2, 3.9, and 4.7 inches (80, 100, and 120 millimeters). “APO” stands for “apochromatic,” which means the main optic has a high degree of color correction built in.
At the heart of all three scopes are two-element objective lenses of extra-low dispersion (ED) glass. Each front element is Schott BK-7, while the rear element is FPL-53, two of the most advanced types of glass available. And Sky-Watcher USA gives both state-of-the-art multicoatings. Together, they have the potential to minimize false color caused by chromatic aberration (a defect where colors don’t focus at the same place) and maximize image contrast. But how do they perform in actual use?
