1. Camera Lens Nahum D. Solomon Pr. Tim Johnson November 30, 2009 Wentworth Institute of Technology

2. The camera lens design depends on theproperty of light to bend • 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

3. Light rays from a closer point converge farther away from the lens than light beams from a distant point Focal • 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

4. Focal length of lens describes itsmagnifying power • • 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

5. A zoom lens allows choice of any focal length within the lens design range • Angle of view / magnification trade-off • Zooming out” uses shorter focal length, providing wide-angle view • “Zooming in” uses longer focal length, narrowing field of view so objects appear large

6. Zooming in magnifies by cropping the scene tighter than a wide-angle lens • Collection of photos taken from same position with lenses ranging from wide angle to telephoto: 24mm, 35mm, 50mm, 100mm, 200mm, 300mm

7. Lens optics • 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

8. Zooming in is great for Portraits • Zooming in allows filling the frame from a distance • Keeping at a distance allows candid shots • Short depth-of-field nicely blurs background

9. Wide screen Lense • Wide angle lens may introduce perspective distortion Might make pictures appear feather or longer than they really are Allusions

10. Caution when using • Wide-angle close-ups distort facial features, giving a "fish bowl" effect Can make you look weird or scary

11. When to use Wide sceen • Use to capture a large area picture • Used in a crowd • Used to capture a wide building/area

12. Focusing tips • 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

13. Lenses are expensive At times more expensive then the Body of the camera Range from 90$-500 Depending on the zoom length

14. Bibliography: • Self experience • http://cameras.about.com/od/cameratips/Digital_Camera_and_Photography_Tips_How_Tos_and_Tutorials.htm • http://digital-photography-school.com/how-to-use-a-camera-phone • http://en.wikipedia.org/wiki/Photographic_lens • http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/990/ON-CAMERA-LENS/overview.html • http://www.the-digital-picture.com/Canon-Lenses/ • http://www.cambridgeincolour.com/tutorials/camera-lenses.htm • http://www.ehow.com/how-does_4703550_how-camera-works.html