This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionCamera focal length vs crop factor vs angle of view.svg
English: Log-log graphs of focal length vs crop factor vs diagonal, horizontal and vertical angles of view for film or sensors of 3:2 and 4:3 aspect ratios. The yellow line shows an example where 18 mm on 3:2 APS-C is equivalent to 27 mm and yields a vertical angle of 48 degrees. Simulated bitmaps were derived from File:1_times_square_night_2013.jpg.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the licence, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible licence as the original.
This file contains additional information, probably added from the digital camera or scanner used to create or digitise it.
If the file has been modified from its original state, some details may not fully reflect the modified file.
Short title
Camera focal length vs crop factor vs angle of view
Image title
Log-log graphs of focal length vs crop factor vs diagonal, horizontal and vertical angles of view for film or sensors of 3:2 and 4:3 aspect ratios by CMG Lee. The yellow line shows an example where 18 mm on 3:2 general APS-C is equivalent to 27 mm and yields a vertical angle of 48 degrees. Simulated bitmaps were derived from http://commons.wikimedia.org/wiki/File:1_times_square_night_2013.jpg .