On Sunday 16 August 2009 14:42:26 Nick Whitelegg wrote: > The thing I don't really know much about is: how can you get the > field-of-view angle of a photo taken from a digital camera (either a > standalone camera or within a phone)? The formula is : Tan(angle/2)=size of film/(2*focal)
for a standard film you get and a 50mm objective: size of film = 24x36 (diagonal=43.3) so angles are: vertical 27° horizontal 39.6° diagonal 46.8° > I've seen a few explanations on the > web on how you get it from the focal length (which appears to be quoted in > e.g. the N95 specs) but they also require another parameter (the "size of > the film"). Where might I get this from? In fact you don't really need the size of film (captor size). Most of the camera store the focal in both real and equivalent distance. If I take a random picture from a nikon D300 the exif information contain this: Focal Length: 70mm Focal Length In 35mm Film: 105mm Digital zoom ratio: 1.0 So with the equivalent focal and the digital zoom, you can get your angle. -- Vincent MEURISSE _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
