Aspect ratio is a phrase that you’d normally expect to hear when discussing movies or televisions, but as it is a measurement of image proportions, it’s also important in photography. It is also one of those things that is always there, even if you don’t think about it.
Aspect ratio in photography is a description of an image’s vertical and horizontal proportions expressed as two numbers separated by a colon, and composed of similar units of measurement, whether it be inches, centimeters, or feet.
You’ve seen these numbers before, such as 16:9, which is commonly known as widescreen format, and used to describe many TV’s and computer monitors.
16:9 would be an image (or in the case of a TV or monitor, a screen) that is 16 units wide and 9 units tall. Aspect ratio doesn’t describe actual size, as a 16:9 ratio could be 16 inches wide by 9 inches tall, or 16 feet wide and 9 feet tall. The numbers only describe the proportions.
Although it’s not in the scope of this article, movies and film sometimes also use what’s known as cinema terminology to express aspect ratios, such as 1.85:1 (cinema standard widescreen) and 2.39:1 (anamorphic widescreen).
Although you can convert these expressions to standard ratios, for our purposes, we’ll only stick with standard x:y expressions that relate to camera sensors or photographic images.
So why are aspect ratios important to photography?
Primarily, they are important because every image we shoot, as well as every camera we shoot with, has a base aspect ratio. Our camera bases the aspect ratio on the proportions of the sensor, which you cannot change.
However, you can change the resulting image’s aspect ratio, and most importantly, you can change it for creative reasons.
There are actually two types of aspect ratio in photography we need to familiarize ourselves with; the aspect ratio of the camera we’re shooting with, and more importantly, the final aspect ratio we will present our image in.
We, of course, can change the latter in post-processing, for whatever reason we decide.
Some cameras also have settings that allow you to change aspect ratio in-camera before shooting, but this is made possible by the camera software cropping. It’s always better to change the ratio yourself and crop later in post-processing.
Why would we want to change the aspect ratio of a photo?
The main reason – composition.
Changing the aspect ratio in Photoshop or Lightroom is essentially cropping the image to a specific proportion that makes the photo more pleasing to the eye. A wide, sweeping shot of a beach and sky will not look as wide and sweeping in a standard 3:2 presentation as it would in a 16:9 widescreen format. Composing the image in widescreen proportions gives the scene a more open, cinematic feel.
Let’s take a look at the most popular aspect ratios in photography, and what they are commonly used for.
Breakdown of aspect ratios in photography
The 3:2 ratio is probably the most commonly used aspect ratio in photography, due to the fact that it is the standard proportions used with modern DSLR camera sensors.
The reason for this is because it is also the ratio used by classic 35mm film cameras. Digital camera sensors were originally designed to replicate that ratio.
Before photography, artists generally used a set of proportions similar to this because of its visual appeal. The 3:2 format is a great general use ratio, and allows for a fairly wide feel while still capturing vertical elements of a scene.
The 4:3 ratio is a classic format that has its roots in digital point and shoot cameras, which were developed to basically match the proportions of video monitors of the time.
The format is used in point and shoots, many compact cameras, and micro four-thirds systems.
Just as with old TV and video monitors, the 4:3 format has a taller, slimmer look that appears more square to the eye. It is a good creative choice when you need to capture vertical elements of a scene.
The 16:9 ratio is more commonly known as the “widescreen” format.
It was developed as a replacement for the old 4:3 ratio during the advent and implementation of HDTV. Most TV’s and monitors now are created with this format in mind.
The longer, more horizontal format is great for displaying landscapes and other vistas, and creates a cinematic look and feel when used in photography.
The 1:1 ratio, or square format, might be mistaken as a newer format, as it is well-known for its use on the Instagram platform (although photos are no longer forced in that format with the service). However, square images are also the usual ratio for medium-format cameras, as well as a few toy cameras.
This format is a good choice for cropping close and isolating a subject or a scene that doesn’t involve an expansive landscape.
The 5:4 ratio formatted images are primarily used in large-format photography, as many of those cameras use sheet film with dimensions of 5×4 inches.
From a creative standpoint, images using this ratio are almost as tall as they are wide, and are great for capturing vertical elements of a scene.
Finally, the 2:3 ratio is a specialty aspect ratio that is used for images in vertical or portrait orientation.
It is primarily used for portraiture, when elements of the scene (in most cases, a person), align in a vertical orientation.
You can also use vertical formats like 2:3 for landscape photography to capture tall elements within the frame, such as trees and mountains.
Before the advent of digital photography and software, aspect ratios of the camera being used generally dictated what ratio the image would be in.
In the digital age, however, we have the ability to simply and quickly crop in whatever photo software we’re using.
Instead of being bound to a specific format, you can change it. Therefore, changing the look and feel of an image for creative reasons, even after pressing the shutter and recording the image on the sensor.
So now you know a little more about aspect ratios in photography, and why it’s important. What formats do you find yourself using? Do you alter the aspect ratio during post-production? Leave us your comments below!