1. Lenses
Are classified
by their
Focal Length

2. Focal Length
The distance from the optical center of a lens to the front surface of the imaging device.

3. Short Focal Length
Wide Angle View
Wide Angle Lens

4. Short Focal Length
EXAMPLE
Entire Football Team

5. Long Focal Length
Narrow Angle View
Telephoto Lens

6. Long Focal Length
EXAMPLE
One Football Player

7. Zoom Lens
Variable Focal Length

8. Zoom Range
How close to how far a lens can see

9. Lens Speed
How much light can pass through a lens

10. Fast Lens
Lets a great amount of light to pass through

11. Fast Lens Use in the evening, when there isn’t much light.
For low light settings

12. Slow Lens
Lets a small amount of light to pass through

13. Slow Lens
Use this on bright, sunny days
For bright light settings

14. Iris
Adjustable lens opening mechanism

15. Aperture
Hole in center of iris
Measured by f-stops

16. Aperture
Similar to the pupil of your eye

17. Aperture
Can adjust larger or smaller depending on the amount of light

18. Aperture
What type of aperture opening would you use for a sunny day?

19. Aperture
What type of aperture opening would you use for a dark room with only a candle for light?

20. Auto Iris Many cameras have auto iris
Adjusts automatically depending on setting

21. Focus
When subject in viewfinder is sharp and clear.