Aperture, Shutter Speed, ISO - The Three Pillars of Photography

Hey Everybody!

Today I wanted to cover probably the most important fundamental of photography besides maybe knowing how to turn your camera on. This is the “Three Pillars of Photography” which are aperture, shutter speed, and ISO.

In order to be a decent photographer, it is important to learn how to shoot in full manual settings, otherwise you are stuck with whatever image your auto settings spit out. Shooting in manual will increase your photography TREMENDOUSLY, but in order to do this you must learn the how to properly use these three pillars.



HARDWARE The aperture in your camera is a set of blades in your lens that form a diaphragm… a hole, they form a hole. The aperture is much like your pupil, which shrinks and expands to control the amount of light let in.


WHAT IS APERTURE? Aperture is a device in your camera that controls the amount of brightness and depth of field in an image. An aperture that is as small as it can be is called “closed” while an aperture that is as large as it can be is called “wide open”. Aperture is measured in what is called an “f-stop”. The larger number of the f-stop the smaller the hole gets.

BRIGHTNESS The aperture is much like your pupils, the smaller the aperture, the less light is allowed into the camera. Therefore, when shooting in a bright area it is best to use a smaller aperture to prevent your image from being over exposed. When you’re shooting in low light, it is best to use a wider aperture to prevent your image from being under exposed.

DEPTH OF FIELD Aperture is the most important of the pillars due to the fact that it can change the depth of field in an image. This can completely transform an image, making it even better.

When shooting with a wide aperture, you will have a more narrow depth of field, causing the background to be out of focus. This is very popular in portraits like this one I took of my friend Emma. Notice how the leaves behind her are out of focus allowing her to pop out more from the background.


In contrast, when shooting with a closed aperture, your images will have practically everything in focus from whatever is closest to your camera all the way to the mountains a mile away. This is particularly popular with landscape or nature pictures in order to have a very sharp picture of everything in the landscape.

Below is a great diagram to remember while setting your aperture.



HARDWARE The shutter on your camera is a small curtain that is in front of the camera sensor. This curtain is always closed until you take a picture in which it opens and then closes to expose your sensor to light.

WHAT IS SHUTTER SPEED? Shutter speed is the duration of time your camera sensor is open and allowing light into the sensor, or in simple terms it is how long your camera spends taking a picture. This is measured in fractions of a second (ex. 1/1000 - one-one thousandth of a second). The duration of time your shutter is open has several effects on the final outcome of your picture.

BRIGHTNESS The first effect it will have is how bright your image is or how “exposed” it is. When you have a quick shutter speed like 1/1000, your camera will be open for an incredibly small amount of time. Therefore, your sensor will be exposed to much less light, resulting in a darker image compared to a picture taken at 1/2, where your shutter is open for half a second.

MOTION BLUR The second effect that shutter speed controls is the amount of motion blur in a picture. Just like with brightness, the longer your shutter is open, the more motion blur your image will have. Therefore, when you are taking pictures of fast moving objects like sports or birds, it is best to have a high shutter speed to get a sharp image with no motion blur.

On the other hand, have ever seen a picture of a city at night where all the car lights stream across the picture creating an amazing effect? This is done with a very slow shutter speed, usually longer than a second. The term for this is “Long Exposure”. Although, you will need a tripod in order to create a picture like this without any additional blur from your camera shaking while you hold it.

Below is a great diagram to remember while setting your shutter speed.

shutter crop.jpg


HARDWARE ISO is a button on your camera that effects the sensor’s sensitivity to light… Yup, pretty simple.

WHAT IS ISO? Just like aperture and shutter speed, ISO also impacts the brightness of your images. Luckily, ISO isn’t as complex as the other two. ISO simply darkens or lightens your photo depending on the measured number.

BRIGHTNESS Depending on the ISO number, your image will be brighter or darker. For example an image taken at a higher number like ISO 800 will be brighter than an image taken at a lower number like ISO 100. This is helpful when it comes to shooting in low light situations or when your shutter speed is high.

GRAIN Increasing your ISO level will increase the brightness of your image, but there is a big downside. As you increase your ISO levels, you are increasing the “grain” or “noise” in the image. So when the image gets brighter, it gets noisier. Therefore, you should only increase your ISO when you can no longer adjust the brightness through your aperture and shutter speed. In order to have the sharpest image possible, you should have your camera set to its native ISO. The native ISO is the lowest number ISO it can be, which in turn produces the least amount of grain.

Below is a great diagram to remember while setting your ISO.


Understanding these three pillars and learning how to balance them will allow you to take your photography to the next level. Go out and practice shooting in different situations like sports or portraits. Once you learn what is best for wide variety of different situations you will be able to quickly switch up your settings, take the shot, and get outstanding results.

I hope you all learned something today!

- Evan James