Free working distance
In close-up photography, the distance between the front of the lens and the subject; increases as the focal length increases; ...
-Free working distance - distance between the front of the lens and the subject.
-Fresnel lens - condenser lens used on a spotlight to gather together the rays of light coming from a source and direct them into a narrow beam.
designed to focus continuously from infinity down to a reproduction ratio of 1: 2, or with a matched extension ring or teleconverter down to 1: 1; available in normal or telephoto focal lengths to provide a variety of free working distances; ...
The free working distance is defined as the distance between the front lens of the objective and the cover slip or uncovered sample.
 See also: Factor, View, TTL, Iris, Viewfinder
  
|
RSS
