So, you decided to start taking photography a little bit more seriously, and you wanted to start taking photos manually. Great! Whether it’s an old point and shoot that you wanted to mess around with, or an expensive camera, the basic functions of a camera are the same. The things that one controls in manual mode are ISO, shutter speed, and aperture. Today, we’ll be taking a look at ISO.
What is ISO?
ISO stands for International Organization for Standardization, and in the most simplest terms is how sensitive your sensor is to light. Whether you pronounce it eye-ess-oh or eye-so, the most important thing is knowing what its function in digital photography is. Not only will understanding ISO help you ease into manual photography, it will ultimately help you with the quality of your photographs.
Why Should One Be In Control Of The ISO?
There are three main reasons one should be in control of the ISO:
Obviously, if you’re not relying on the camera helping you throughout every function by using auto, you’re going to need to know how to control every aspect of the camera. If you don’t know what ISO does, and you keep the camera on manual mode with a fast shutter speed and low ISO and want to take a picture before the sun goes down, it’s going to end up dark.
This will be further explained in the picture representations later in this article, but generally speaking, the higher the ISO, the higher of a probability of the picture being noisier. Sometimes, it’s unavoidable. In the end, what matters is how much noise you find acceptable in your photos.
Because It’s Part Of The Equation That Makes It Feel Like YOUR Photo
I have extremely high standards for photographs that I take of people, animals, landscapes, etc. If it’s a planned shot, and not just a quick shot to document something, I will always use manual mode or aperture priority mode. If you set your camera to auto, all you’re doing is just pressing the button. If you set it to manual, you’re in control of every aspect of the camera. If you set it to aperture priority, you’re in control of the ISO and aperture, while the camera takes care of setting the shutter speed (which is perfect for scenery that changes). You want it to feel like your creation – not something that just anyone could do.
Explaining ISO Tangibly
Let’s use aperture priority as an example for simplicity. If I’m using an f/1.8 lens, this will give it a shallow depth of frame, and I’m setting it the aperture at f/1.8, it’ll be what photographers call “wide open”. In this instance, the shutter speed will be faster because it’s letting more light in. When you want a deeper depth of field, you have to compromise the amount of light coming in. If you’re taking pictures of moving objects, this can be difficult because they’ll end up blurry.
But fear not – camera technology is awesome! You can bump up the ISO in lower light settings and not have to compromise shutter speed. But how much ISO is too much?
Let’s take a look at these quick pictures I took of a flower as an example. I shot in aperture priority mode at f/1.8 with varying ISOs to showcase noise at around 5:30PM (Arizona time), so the sun was starting to go down.
Most camera will have a base ISO of ISO 100 or ISO 200. The closer to this ISO, the less noise you’re going to encounter.
Still looking good at ISO 640. Though, 640 is a little bit overkill with how much light there still was outside.
Here, you can see things starting to get a little bit noisier, especially in the background. You’d generally use this type of ISO in low light situations.
Huge difference between this one and the last one, right? Not something you’d want to showcase professionally, but it’s usable in personal situations.
Granted, your mileage may vary for your camera. Your camera could start getting noisy at ISO 640 if you have something like a point and shoot, or you could have better noise performance with a full frame camera.
There is no be-all-end-all advice when it comes to digital cameras and ISO performance. The general rule of thumb is “the lower the ISO, the better”, but in all honesty, part of learning photography is practicing in certain situations, and getting a feel for how much is too much.