1. Focal length is the most important specification of your lens
2. Understanding camera lenses adds more creative control to your photography
3. Camera lenses are compromised with "Lens Elements"
4. Each of elements directs the path of light rays to recreate the image as accurately as possible
5. Focal length is the distance from the front element of the lens to the point at which light passing
through the lens is focused
6. Focal length tells you the length and magnifying power of the lens
7. Focal length can be fixed
8. A short local length of up to 35mm is considered wide angle
9. Focal length between 35mm and 70mm is considered normal
10. Focal lengths greater than 80mm are considered telephoto range
11. Wide angle lenses have short focal lengths
12. Telephoto lenses have longer corresponding focal lengths
13. Focal length can also affect the sharpness of a photo
14. Long focal lengths require shorter exposure times
15. A prime lens has a single fixed focal length
16. A zoom lens has a range of focal lengths
17. Zoom lenses are more convenient to use than prime lenses
18. Prime lenses perform better and are less expensive than zoom lenses
19. The widest aperture a lens can be opened to is called the maximum aperture
20. Prime lenses have a set maximum length
21. Zoom lenses have variable maximum aperture settings at different focal lengths
22. Lenses with a constant aperture at a low f-number are more expensive because the have a larger
diameter with more glass
23. Lenses with a constant aperture are considered "fast lenses" because the larger aperture allows in
more light resulting in faster shutter speed.
24. Fats lenses and long telephoto lenses have large diameters.
25. Common lens sizes are 58mm, 67mm, 72mm, and 77mm