What is a Focal Length

The light comes from the front element of your lens to the back element and then to the sensor. The distance between the digital sensor and the back element is called the a Focal Length. It is usually measured in mm. If this distance is small, you have a very wide field of view.

  • 14 mm - 28 mm : wide angle

  • 50 mm : standard

  • 100+ mm : telephoto (compressed or magnified field of view)

These numbers refer to crop factor 1 (35 mm film size sensor).

See this online calculator to determine the required lens focal length to take a picture in order to generate an image of a certain size on the film (or the CCD/C-MOS image).

No comments :

Post a Comment