2 Replies Latest reply on Mar 2, 2015 2:38 PM by getho

    calculate field of view or focal length from crop

    getho Level 1

      Is there a way to do this or a plugin anyone knows of?

       

      (If you have a shot on a 14mm but you crop in to the centre of it, it would be nice to know what the equivalent focal length the crop equals)

        • 1. Re: calculate field of view or focal length from crop
          elie-d Level 4

          Set the Info Overlay to show the new cropped dimensions. In the simplest case where the aspect ratio of the crop is the same as the original image, divide an original side by the corresponding crop side to obtain the crop factor. If the original is from a full-frame camera, the 35 mm. equivalent is the focal length times the crop factor. If the camera has a sensor that is less than 24x36 mm., the total crop factor is the camera's crop factor times the "in LR" crop factor. Thus, if you have a Canon 7D which has a 5184x3456 pixels sensor and a 1.6 crop factor and you crop the image to 2592x1728, the resultant crop factor is 3.2 and your 14 mm. lens will have the FOV of a 44.8 mm. lens on a 35 mm. camera. If the LR crop has a different aspect ratio than the original, the equivalence is, of course, different for the height and width.

          • 2. Re: calculate field of view or focal length from crop
            getho Level 1

            thanks elie  I was hoping their might be a plugin that would add the info into the metadata or something, but yes the calculator works!  It was interesting actually.  I had a client that specified no super wide shots AFTER a shoot.  So I cropped in my 14mm shots what felt like quite a lot but most still equated to 16-19mm.