Lesson 4 • Exposure
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The document discusses the exposure triangle of aperture, shutter speed, and ISO, which are the three key factors that determine the amount of light in a photograph. Aperture refers to the size of the opening in the camera lens and controls depth of field. Shutter speed refers to how fast or slow the camera shutter opens and controls motion blur. ISO refers to the camera sensor's sensitivity to light and impacts image noise. To achieve a properly exposed photo, the photographer must balance these three elements of the exposure triangle.
Lesson 4 • Exposure
- 1. Today, I will learn… Exposure: Aperture Shutter Speed ISO The Exposure Triangle Learning Goals
- 2. Exposure
- 3. What is Exposure? In photography, exposure is the amount of light in your image. Exposure can be determined by three key factors: Aperture Shutter Speed ISO
- 4. Exposure as a Window Shutter Speed Aperture ISO
- 5. Aperture Aperture refers to the diaphragm within your camera lens, and how big or small the opening is The smaller the opening = less light Larger the opening = more light Measured in f-stops Smaller f-stop number = more light Larger f-stop number = less light
- 6. Aperture Aperture also controls your depth of field (how much of the image is in focus) The smaller the f-stop (larger aperture) the less or narrower depth of field The large the f-stop (small aperture) the more or wider depth of field
- 7. More light Less light Narrow DOF Wide DOF
- 10. f 1.4
- 11. Shutter Speed Shutter Speed refers to how fast or slow your camera shutter will open to receive light It is measured in seconds and fractions of seconds, for example; 1/1000th second = fast shutter, less light 15 seconds = slow shutter, more light
- 12. Shutter Speed Shutter Speed also controls how much motion blur is in your image Fast shutter speed (i.e. 1/1000) = less motion blur, sharper image (freezes time) Slow shutter speed (i.e. 1/15) = more motion blur, blurrier image (demonstrates motion) 1/15 1/60 1/250 1/1000
- 13. More light Less light More motion blur Less motion blur 15s 8s 4s 1s ½ ¼ 1/8 1/15 1/30 1/60 1/125 1/250
- 17. 36 minute Shutter Speed!
- 18. ISO ISO refers to how sensitive your camera’s digital sensor (or film) is to light It is measured in doubling or halving the previous ISO stop; 100 ISO = less sensitive 6400 ISO = very sensitive
- 19. ISO ISO also controls how much grain (noise) is in your image Low ISO (i.e. 100) = less noise, smoother/cleaner image High ISO (i.e. 3200) = more noise, more grain
- 20. More light Less light More noise Less noise 6400 3200 1600 800 400 200 100 ISO
- 24. Exposure However, in order to achieve excellent results, you need to think about all three exposure elements These three elements work together to create a properly exposed image An imbalance of any of the elements can create an underexposed or overexposed image Exposure Aperture ShutterSpeed ISO
- 26. Exposure Underexposed loss of shadow detail For example, a picture in a cave, you wouldn’t be able to make out the contours of the rocks/stones Overexposed loss of highlight detail For example, picture of the sky on a bright day, you wouldn’t be able to make out the clouds
- 28. Practice Aperture Use Aperture Priority mode Place items on a table at different distances Experiment with adjusting your aperture (f-stop) to focus on the different elements, and then have all elements in focus