Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

F-number of camera lenses

  1. Nov 29, 2008 #1
    I was reading on the f-number of lenses for cameras...somewhere in the text, they stated that the area of the image is proportional to q2, in which q is image distance. I figured the area to be proportional to q, but I don't really see it as q2...so how does this work out?
  2. jcsd
  3. Dec 1, 2008 #2

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor

    The f/# doesn't affect the field of view, so I'm not sure what you mean, exactly. The image *brightness* goes as the square of the f/#, but that's different.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook