The technical definition of a telephoto lens is one with a focal length greater (or longer) than 50mm (on the 35mm/full frame forma), but the telephoto range is more generally accepted to begin at ...

Learn more › Believe it. Adoram’s ProOptic 500mm f/6.3 ($160, direct; adorama.com) shares all the strengths-and drawbacks-of inexpensive catadioptric lenses. Often called mirror or reflex lenses, ...

[Snappiness] has one, and also having a liking for waist-level viewfinders as found on twin-lens reflex cameras ... viewfinder meanwhile uses a lens, a mirror, and a Fresnel lens, and if you ...

SLRs employ a mirror that directs light from the lenses into a viewfinder so a photographer can compose a shot. This reflex mirror flips out of the way when the photo is taken, letting the light ...

In the reflex design scheme, light travels through a single lens and a mirror is used to reflect a portion of that light through the view finder - hence the name Single Lens Reflex.

In the most literal sense, a DSLR camera is a digital single-lens reflex camera. Inside the camera body is a mirror that reflects the light coming from the lens up into an optical viewfinder ...

Twin-lens cameras like the famous Rolleiflex have two identical lenses one about the other, with one bouncing off a mirror so you can compose, and another exposing the film. The design is made to ...

The 2,000mm F/11 is actually a reflex lens, which uses mirrors to alter the path of light through the lens and gives it a field of view equal to a much longer lens. It has a fixed F/11 aperture, which ...