In a machine-vision system, a camera lens serves one purpose: It gathers light and focuses an image on the camera's sensor. Thus, vision-system designers must treat lenses as key elements in ...

Photography is full of fancy terms and complicated science, but we are here to explain it all to you in simpler terms. Today we are focusing on focal length. This term gets thrown around often, ...

SEATTLE—Primes are single focal length lenses, which can be designed with a relatively few optical elements and thus are capable of transmitting a lot of light to the film or digital camera sensor.

The F-number of a photographic lens is a measure of its light-gathering ability, and is expressed as its aperture diameter divided by its focal length. Lenses with low F-numbers are prized by ...

If you're getting started with portrait photography, one of the biggest questions is: what lens should I use for portraits? With the best portrait lenses coming in so many options – from affordable ...

I recently tested the astroimaging capability of the 20mm Sigma f1.4 DG HSM Art lens with my two DSLR cameras. Released in fall 2015, this Sigma lens has 15 elements in 11 groups. The optics contain ...