Key Takeaways:
When Astronomy asked me to test Orion Telescopes and Binoculars’ latest 4-inch apochromatic refractor, I got excited by the potential of such an instrument. The ED102T CF Triplet boasts 4 inches (102 millimeters) of aperture and a focal length of 714mm. Those numbers work out to a photographic speed of f/7.0, making this a pretty “fast” system that offers a wide field of view for visual observing or astrophotography.