In photography, ISO does not stand for “in search of” but rather “International Organization for Standardization” – that’s a mouthful! There’s a long history of why it is called ISO, but I won’t bore you with the details. 

ISO brightens or darkens a photo or—as we’ve already learned—the level of exposure. An increase in ISO makes an image brighter, and a decrease makes the image darker. ISO helps a lot when you’re photographing in darker environments. 

As you increase the ISO, the brightness of the photo doubles. If you start with an ISO 100 but find it too dark, you can increase it to an ISO 200. The next setting would be 400, and so forth. Base ISO is the lowest ISO setting DSLR cameras can have. My camera has a base ISO of 100. Keeping the ISO at the base is best to ensure the highest quality image. This is not always possible when in low-lit areas. 

Too high an ISO makes the photo grainy. When a photo is grainy, the photography term is noise—and we don’t like noise! Only raise ISO if you can’t brighten with shutter speed and/or aperture. 

Now we’ve learned about the three pillars of exposure – shutter speed, aperture and ISO. It’s essential to use all three settings to ensure the best image. Photography Life suggests:

1. Figure out the depth of field you want – do you like the background blurred or the whole image sharp? Use the f-stop that will give you the depth of field you desire.
2. Set the shutter speed to get the proper brightness.
3. If the shutter speed decreases the photo’s sharpness, dial back the shutter speed and raise the ISO. 

Now that we know the basics, we can dive into taking some photographs and using different apps and editing tools.