Photography Understanding Exposure Shutter Speed Aperture ISO Kam

Photography Understanding Exposure: Shutter Speed + Aperture + ISO Kam Mistry July-2013

�What you need: � Camera that has a manual mode

What is Exposure: Definition: �Exposure is the amount of light collected by the sensor in your camera during a single picture

What is Exposure: �Light hitting the sensor �Generates the image �Simple, right?

An analogy, please: � Think of the camera senor as a bucket �And light as rain

�Question: How do you know that you are correctly exposed? �Use the light meter

�The light meter is built into your camera �Use the light meter to “guide” your exposure setting

So, how do I set the correct exposure setting?

Before I explain that, we need to understand three variables that make up exposure.

The Exposure Triangle:

The Exposure Triangle: Exposure = Shutter-speed + Aperture + ISO

Shutter-speed �There is a curtain in-front of the camera senor �The length of time the shutter curtain is open is called shutter-speed �The “curtain” can be open for a long time (1 s, 5 s, 10 s, 30 s, etc. ) �The “curtain” can be open for short time (1/60 s, 1/120 s, 1/500 s, 1/1000 s, etc, )

Shutter-speed �Slow Shutter-speed (5 s) �Senor is exposed to light for a longer period of

Shutter-speed �Fast Shutter-speed (1/1000 s) �Senor is exposed to light for a short period of time

Shutter-speed �Comparing Shutter-speed:

Aperture �Aperture is “the size of the opening in the lens when a picture is taken” �It’s located on the lens �The Aperture opening can be small = less light on the senor �The Aperture opening can be large = more light on the senor

Aperture �Aperture is measured in ‘f- stops’ �Moving from one f-stop to the next doubles or halves the size of the amount of opening in your lens

Aperture �Aperture controls the “Depth of Field” of the image

Aperture �Large Aperture (F 2)

Aperture �Small Aperture (F 16)

ISO �ISO measures the light sensitivity of the image sensor �The lower the ISO number less sensitive the senor is to light �The higher the ISO number the more sensitive the senor is to light

ISO �Analogy: �Pouring water on: ISO 100 800 1600 Similar to Sensitivity Newspaper Low Sponge Medium Tissue paper High

ISO Low High No Grainy Medium Little Grain

ISO � Use low ISO when in “good” lighting situation (ISO 100)

ISO � Use high ISO when in “poor” lighting situation (ISO 1600)

ISO �Comparison

ISO �Question: What ISO should I use? �Am I hand holding the camera? �Is my subject moving? �Can I get away with Grain?

Recap: The Exposure Triangle: Exposure = Shutter-speed + Aperture + ISO

Example: Camera Simulator: �http: //camerasim. com/camera-simulator/

Where to start? �Use the 4 -4 -4 rule: �Aperture: F 4 �Shutter-speed: 1/400 th �ISO: 400 �Adjust the exposure so that your meter is zeroed:

References �Book: �Understanding Exposure, 3 rd Edition: How to Shoot Great Photographs with Any Camera by Bryan Peterson �Web: �http: //digital-photography-school. com/

Questions?