Watch the video: What is focal length? Take two 50mm lenses: an f/1.8 and an f/1.2. Even though they both have the same 50mm focal length, they're not the same physical length – and neither of them is ...

This article is the third in a series teaching the basics of photography. We started by learning about the properties of light and how an image is created, and we also learned how a lens bends light ...

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 ...

How to select the best focal length; Why wide-angle lenses?; Zoom or Prime?; Telephoto lenses; Focal length analysis; All the information you need to select the right lens for landscapes. A focal ...

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 ...

Part I this monograph describes a photo-electric lens test bench capable of measuring lenses of focal length from 12mm to 1m. Designed specifically for Television applications, it gives the 'optical ...

Perspective in an image is all about the relationships between objects in the scene; specifically their relative sizes and positions … Perspective in an image is all about the relationships between ...