20 FACTS ABOUT LENSES:
1. All lenses are comprised of several "lens elements" (NOT INCLUDING THE SIMPILIST OF LENSES)
2. Elements direct the path of light rays to copy the image as accurately as possible on the digital
sensor
3. Focal length of a lens determines its angle of view, & also how much the subject will be
magnified for a given position
4. Wide angle lenses have short focal lengths
5. Short focal length of up to 35mm is considered Wide angle
6. A prime lens has a single fixed focal length
7. A zoom lens has range of focal lengths (OPPOSITE OF PRIME LENS)
8. Zoom lenses are easier to use but Prime lenses perform better
9. Telephoto lenses have longer corresponding focal lengths
10. Perspective control can be a compositional tool, & often determines one's choice in focal length
11. Aperture range of a lens is the amount that the lens can open up or close down to let in more or
less light, respectively
12. The larger the aperture openings are going to have a lower f-number
13. Lenses w/ a greater range of aperture settings provide greater exposure options & depth of field
14. Portraits, Indoor Sports / theater = large maximum apertures
15. Fast shutter speeds prevent motion blur
16. Fast lenses & long telephoto lenses have larger diameters
17. Image stabilization is to reduce camera shake as if you were shooting w/ a faster shutter speed
than your actually in
18. Most lens manufacturers have several zoom lenses with constant maximum apertures
19. A zoom lens with only 1 aperture number has a constant maximum aperture
20. Prime / zoom lenses let you shoot from a good working distance