Back to basics
Brad Stephens, Staff Photographer
Whenever someone asks me to teach them about photography my first question is always about their familiarity with the exposure triangle. The exposure triangle is the most fundamental area of photography and consists of three settings. ISO which determines how sensitive your camera is to light, Shutter Speed which controls how long your sensor is exposed to light, and Aperture (or f stops) which adjusts the contraction of the aperture blades. Each changes an image in ways you may or may not desire for your specific composition which I will explain here in simple terms.
Here is a simple graphic to help visualize the exposure triangle.
This image is a composite of two pictures that use the same settings except ISO. Increasing the ISO makes images brighter because the sensor accepts more light.
These images show the difference that shutter speed makes. The image on the left used a higher shutter speed so the leaf has no motion blur. The image on the right has a lower shutter speed so the leaf has more motion blur.
These images show the difference aperture makes. The image on the left uses a lower aperture so less of the background is in focus. The image on the left uses a higher aperture so more of the background is in focus.
This image used a higher aperture letting the majority of the frame be in focus.
This image used a high shutter speed allowing the roller coaster to be in focus with no motion blur.
When taking photos at night or in darker situations you are often required to raise your ISO, but you want to be conservative with it. The higher you raise your ISO the more noise (grain) will be introduced into your image.
