Samyang 500mm ƒ/6.3 DX mirror lens

Long focal length lenses for SLR cameras are mostly one of two types – refractors (true lenses) or “mirror” lenses (actually Cassegrain telescopes). Large aperture long lenses are big, heavy, and expensive, but they can perform really well. Mirror lenses are much smaller, lighter, and usually a lot cheaper. However they are fixed aperture, usually … Read more