Tuesday Tip: ISO for Beginners
This blog post is my attempt at “dumbing down” ISO for those just starting out in photography. I’ve been told by a number of people that I’m good at taking complicated concepts and making them easy to understand. You be the judge.
What is ISO?
ISO actually comes from film photography and was used to describe how sensitive film was to light. According to Digital Photography School, in digital photography “ISO measures the sensitivity of the image sensor.” ISO settings usually range from 100 – 1600+ on DSLRs, where 100 is considered “normal.”
When Should I Adjust My ISO?
The general rule of thumb is to shoot at the lowest ISO setting possible, because it provides the finest grain (i.e. it makes your photos crisp). However, you may consider adjusting your ISO in low lighting situations when you don’t have a tripod and need your shutter speed to be quick. As I mentioned above, ISO determines how sensitive your camera is to light. So, the lower the lighting, the more sensitive your camera needs to be in order to shoot a subject without blur. Here are some examples of places/situations you may want to use a higher ISO setting:
- Indoor gatherings without a lot of natural light
- Sports games where the subjects are moving quickly
- Outdoor sunsets
- Nighttime shots
How Do ISO Settings Affect My Photos?
The higher the ISO setting, the more “noise” you will have in your photos. In other words, they will look grainier than they would at lower ISO settings. However, your images will be sharper at a higher ISO when the lighting conditions are poor. Below is a series of photos taken in my dining room at night under tungsten lights. I didn’t use a tripod, so you’ll notice the lower ISO setting photos are blurry, while the higher ISO setting photos are sharper with more grain. (Be sure to click on each photo to view the full size. You’ll be able to see the differences better, especially on the cherry table in the background).
Shutter Speed 1 / 2.5
Shutter Speed 1/6
Shutter Speed 1/10
Shutter Speed 1/15
While it’s important to understand this concept, and test it using your own photo subjects, most cameras have an “Auto ISO” setting. I use this setting most of the time, so I can focus on composition and aperture. I find that my camera does a decent job of setting the ISO, but it’s still fun to experiment from time to time!
What has been your experience with ISO? Comment below with tips and tricks.