Transcript Slide 1
Nahum D. Solomon Pr. Tim Johnson November 30, 2009 Wentworth Institute of Technology Light is bent when it passes between substances having different densities The camera lens bends light in a precise manner, redirecting rays to converge at a point Lens focal length is defined by the distance between lens and focused image on sensor of a subject at infinity. Focal length is often referred to as “angle of view” by photographers • On digital cameras, focal length is often expressed as 35mm film camera equivalent • Higher focal length number indicates a greater image magnification › Telephoto ~100-300mm › Normal ~50mm (human eye) › Wide angle ~18-35mm Angle of view / magnification trade-off Zooming out” uses shorter focal length, providing wideangle view “Zooming in” uses longer focal length, narrowing field of view so objects appear large Collection of photos taken from same position with lenses ranging from wide angle to telephoto: 24mm, 35mm, 50mm, 100mm, 200mm, 300mm A cross-section of a camera lens shows it is constructed of a complex series of multiple lenses The array of concave and convex lens elements is designed to correct for optical aberrations Zooming in allows filling the frame from a distance Keeping at a distance allows candid shots Short depth-of-field nicely blurs background Wide angle lens may introduce perspective distortion Might make pictures appear feather or longer than they really are Allusions Wide-angle close-ups distort facial features, giving a "fish bowl" effect Can make you look weird or scary Use to capture a large area picture › Used in a crowd › Used to capture a wide building/area When you buy a camera, BUY THE LENSE THAT MATHCES THE BODY!!!! The auto focus system adjusts the focus to make the subject in the center of the viewfinder appear critically sharp. Auto focus may have trouble focusing in certain situations › THEN USE MANUAL ZOOM At times more expensive then the Body of the camera Range from 90$-500 Depending on the zoom length Self experience http://cameras.about.com/od/cameratips/Digital_C amera_and_Photography_Tips_How_Tos_and_Tutorial s.htm http://digital-photography-school.com/how-to-usea-camera-phone http://en.wikipedia.org/wiki/Photographic_lens http://www.cs.mtu.edu/~shene/DigiCam/UserGuide/990/ON-CAMERA-LENS/overview.html http://www.the-digital-picture.com/Canon-Lenses/ http://www.cambridgeincolour.com/tutorials/camer a-lenses.htm http://www.ehow.com/how-does_4703550_howcamera-works.html