ISO: an Explanation for Beginners

How does ISO affect exposure of an image?

The Exposure Triad, Exposure Triangle. Aperture, Shutter Speed, and ISO explained. Photography for DSLR cameras

Photography and the science of light continues with ISO. ISO is part of the Exposure triad or triangle, and works with Aperture and Shutter Speed to determine how your image is exposed. ISO in a nutshell is how sensitive your camera is to the light. I have already written about Exposure, Aperture, and Shutter Speed.

A lower ISO- 100 means the camera sensor is less sensitive to light. This setting is used in bright light situations to prevent overexposure. Bright midday sunlight, settings with bright light reflecting snow, etc. are times to use a lower ISO. Higher ISO settings are for situations with less light; cloudy days, dusk, when the snow is setting, nighttime, and indoors where there isn't a lot light. 

Increasing the ISO can work well in low light situations to allow you to use a faster shutter speed and smaller aperture to get good crisp focus and deeper depth of field. However, Using a higher ISO can increase the "noise" in your image, making it grainier and foggy looking. 

Below you can see the same shot with the only setting changed being ISO. I started with a low light situation with no flash. I wanted to show  how increasing ISO increases the light in your image. If you enlarge each image, you will notice the increase grain in the photo as the light increases as well.  My settings were f1.8, ss 1/60 and I adjusted ISO from 100 up to 6400. 

This one 50mm 1/250 f1.8 ISO 400 with on camera flash. 
If you notice some wear and tear on these rings, it's been earned. They will be 17 years old August 2017. My husband and I have worn them and earned those scratches, dents and dings, with love, sweat, tears, and just a couple of beers. 

ISO tutorial for beginners. Photography tips and tricks, How to use your DSLR camera

 I am an Amazon Affiliate. Blogging and sharing information takes a lot of time and effort! So if you are so inclined, follow my link to learn more about Exposure on Amazon! The link below will take you to a search for a huge selection of books all about photography exposure, aperture, shutter speed, and ISO. 

Read about Photography Exposure

Read about Photography Exposure