What Does ISO Mean? How Does it Affect my Photos?



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I am going to keep this post short and sweet. ISO can end up being a huge topic and for a beginner, people tend to talk about a lot of stuff you have no interest in knowing. I'll keep what I write limited to the basics.

To start off with, I'll tell you that ISO is an acronym. It stands for the International Organization of Standardization, an organization that has to do with camera sensors and their measurements. It's an old acronym that's been carried over since the good ol' days of film. You don't need to know any of this. It has no impact on your photography.

What you do need to know is how ISO affects the photos you take. In general, low ISO values on your camera are good. The lower your ISO setting (100-200), the more normal your camera sensor's sensitivity. The lower the sensitivity, the less noise or grain in the resulting photo. As you increase your ISO value, noise or grain is introduced into your photos as small specks or tiny little dots. You don't want this. Noise is bad.

Why would you want to go from a normal sensor sensitivity to a higher one? Well, if you're taking photos in bright daylight, your camera's normal sensitivity is fine. There's tons of light to enter through the lens and you don't need to compensate for anything. It's only as you enter darker, lower light environments that you may need to crank up the sensitivity. Say you're in a dark room and your photos are coming out underexposed (dark). If you increase your ISO value, the sensor will become more sensitive to light (like an amplifier), which will, in turn, brighten up the photos. This brightness comes at a price though. That price is grain. So there's always a trade off. Just remember, the lower the ISO number on your camera, the better.

I've written a few posts on the blog that have to do with ISO, what it means, and how it works. Take a look at them by clicking through below. I was quite thorough, so they may be very helpful if you're interested in leaning more about this topic.

Understanding Basic Camera ISO Settings
When Should I Change My ISO Setting?
Photography Basics: Shutter Speed, Aperture & ISO
What Does ISO Mean? How Does it Affect my Photos? was posted on 02-12-2020 by JGaulard in the General Photography Talk forum. Click to visit our most recent posts or return to the photography forum homepage.