Unformatted text preview: At that spacing, how many pixels would this camera use? A = Area of Photosensor = 5 x 7 mm 2 = 3.5 x 10-5 m 2 d 2 = Area of Pixel = 5.02 x 10-12 m 2 Number of pixels in photosensor = A/d 2 = 7.0 megapixels . FYI: The “f-number” (also called “f-stop”) of a lens is written as “f/#’, and is simply the focal length divided by the diameter of the effective aperture, so that as you open the aperture (letting more light in, so you can take pictures more quickly), the f-number decreases. At large apertures – f/4 and above – resolution is typically limited by lens aber-rations. At small apertures, starting around f/16 for the 35mm format, the resolution is limited by diffraction. Photosensor lens Focal length, f = 10 mm Aperture, D = 3 mm d Photosensor: 7 mm 5 mm Pixel Solution...
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- Spring '07
- Diffraction, Aperture, F-number, spot size