Using binoculars (orange circle) look for a large, upright, S-shaped asterism of dim stars in the space between Alnilam and Mintaka. Sigma Orionis, the medium-bright star shining less than a finger's width to the lower right (or 0.8 degrees southwest of) Alnitak, is a beautiful little ...
Modern refractor/refracting telescopes come in two styles: achromatic and apochromatic. Each of these styles is designed to reduce chromatic aberration (i.e. color fringing or color distortion/dispersion) differently, which is a common problem in lenses (i.e. refractors) when colors are refracted...