What is Auto ISO
by Camera Geek Wannabe
LCD Screen Showing AUTO ISO Range
"What is Auto ISO?"
Auto ISO is a camera setting that is very underused. Photographers shy away from it because they don't understand why they would want to use Auto ISO. The ISO setting can be thought of as a setting that dictates how much light is needed to strike your camera's sensor to get a good exposure.
A low ISO number means the camera sensor's sensitivity to light is normal. A high ISO setting means the camera doesn't need as much light to get a good exposure-think of it as if the sensor is more sensitive to light.
WHY SET ISO TO A LOW NUMBER
We've all heard the standard photography advice to set your ISO as low as possible to keep digital noise
at a minimum. In other words if you set your ISO too high, your camera has to artificially amplify the signal that the sensor has produced from a very low level of light striking it. This results in a lack of sharpness and digital noise.
WHY SET ISO TO A HIGH NUMBER
A higher ISO setting gives you the advantage of being able to use a fast shutter speed to freeze the action because the shutter is open such a shorter time frame. This helps you with sports and wildlife photography as well as being able to get sharp pictures without using a flash in dimly lit situations.AUTO ISO
lets you set both the aperture and the shutter speed settings and your camera automatically sets the proper ISO setting to get a good exposure. You can control the range of things in focus within your photo, known as the Depth of Field
when you set the size of the lens opening, called aperture. With AUTO ISO you can also set the shutter speed to get the right amount of sharpness or Intentional Blur
that you want. The ISO, the shutter speed, and the aperture all come into play together to help you get the proper Photo Exposure
Here is the full article on Setting ISO to AUTO