1. Exposure Variables ISO and Shutter Speed

2. Intro  Exposure and composition are dependent on three variables:  ISO setting  shutter speed  aperture setting

3. ISO setting  The ISO “speed” determines how sensitive the camera’s image sensor is to light.  A high ISO speed requires less light, but produces a grainier image.  A low ISO speed produces a clearer image, but requires more light.  Source: http://camerasim.com/slr-camera-explained/

4. Common ISO Settings  100 – bright, sunny day outside  200 – cloudy day outside  400 – well-lit indoor  800 – darker indoor situation  1600 – night/low light

5. Shutter speed setting  Shutter speed is how long the shutter “curtain” stays open to allow light into the camera.  A fast shutter speed allows you to “freeze” action in a photo, but reduces the incoming light.  A slow shutter speed lets in more light, but can cause motion blur in the photo  Source: http://camerasim.com/slr-camera-explained/

6. Shutter Speed setting  Setting number represents a FRACTION (250 = 1/250 of second)  Big number = less light  Small number = more light

7. Common Shutter Speed Settings  Common settings: B, 1 (1 sec.), 2 (1/2 sec.), 4, 8, 15, 30, 60, 125, 250, 500, 1000, 2000, 4000  Any number with “ behind it indicates seconds

8. Exposure Variables Aperture

9. Intro  The aperture is the size of the hole light passes through at the moment a photo is taken.  Source: http://camerasim.com/slr-camera-explained/

10. Aperture  The aperture setting is also referred to as f/number or f/stop.  A high f/number makes more things in focus, but reduces the amount of light entering the camera.  A low f/number makes backgrounds blurry and allows more light into the camera.  Source: http://camerasim.com/slr-camera-explained/

11. Common Settings  2, 2.8, 4, 5.6, 8, 11, 16, 22 (every other setting is twice as much or half as much light as last setting)

12. Depth of Field  Depth of field is the range of focus.  A long depth of field means more will be in focus – the foreground, middle ground and background.  A short depth of field means less will be in focus – the foreground only, for example.

13. In a nutshell…  The larger the f-stop (bigger number), the longer the depth of field.  The shorter the f-stop (smaller number), the shorter the depth of field.

14. Discussion Time  Get into groups of three.  Everyone in a group will receive a sheet of paper.  Everyone will get 30 seconds to write down important phrases about their word.  Each person will share what they know about the subject using only the words written on their sheet to help them.  Mrs. Bass will call on someone from each group to summarize what each group knows about the topics.

15. Equivalent Exposure

16. Intro  For each photo, there are multiple settings that will give proper exposure. This concept is equivalent exposure. A photographer chooses the settings based on the desired look of the photo.

17. Motion/Blur  If motion or blur is the biggest concern, the photographer sets the shutter speed first, and then sets the aperture setting.

18. Explanation  For each shutter speed increase, the aperture setting must decrease to give same amount of light.  Less time open, so opening needs to be larger.  For each shutter speed decrease, the aperture setting must increase to give the same amount of light.  More time open, so opening needs to be smaller.

19. Depth of Field (DOF)  If depth of field is the biggest concern, the photographer sets the aperture first and then sets the shutter speed setting.

20. Explanation  For each aperture setting decrease, the shutter speed setting must increase to give same amount of light.  Larger opening, so less time is needed open.  For each aperture setting increase, the shutter speed setting must decrease to give the same amount of light.  Smaller opening, so more time is needed open.

21. In a nutshell  When one goes up, the other goes down  When one goes down, the other goes up

22. Exposure Variables Reading the Light Meter

23. Intro  The lens light meter is built into the camera and reads the light that passes through the lens.  The meter displays the amount of light reaching the film based on the ISO, shutter speed and aperture settings.

24. Goal  The goal is to have the arrow in the center value, which is zero on our light meters, because this indicates proper exposure.  To reach this goal, the photographer will have to change the exposure settings until the indicator reaches zero.  Remember: Because of equivalent exposure and that there will be multiple settings to achieve proper exposure.

25. Explanation  The numbers below zero indicate that there is not enough light and that the image will be underexposed.  The numbers above zero indicate there is too much light and the image will be overexposed.

26. Underexposure  If the light meter shows underexposure no matter how much you change your aperture or shutter speed, both settings need to go down and the ISO needs to increase.

27. Overexposure  If the light meter shows overexposure no matter how much you change your aperture or shutter speed, both settings need to go up and your ISO needs to decrease.

28. Discussion Time  Get into groups of three.  Everyone in a group will receive a sheet of paper.  Everyone will get 30 seconds to write down important phrases about their word.  Each person will share what they know about the subject using only the words written on their sheet to help them.  Mrs. Bass will call on someone from each group to summarize what each group knows about the topics.