What is an Aspect Ratio?
With the recent buzz surrounding the release of Oppenheimer, much of the discussion has centered around the best way to experience the film. A major factor in this debate is something called aspect ratio, which significantly influences how visuals appear on screen. While commonly discussed in filmmaking, aspect ratio is just as essential in photography.
This guide will break down what aspect ratios mean in photography, how they impact your work, and why they’re a hot topic when it comes to watching Oppenheimer.
What is an Aspect Ratio?
Some images are wide, like panoramic shots, while others are tall, square, or somewhere in between. Aspect ratio refers to the proportional relationship between an image’s width and height. In photography, understanding aspect ratios is crucial when selecting print sizes, displaying images in various formats, and refining your overall composition.
Aspect ratios are expressed as width to height (written as width:height and pronounced “width to height”). For example, most DSLR and mirrorless cameras capture images in a 3:2 aspect ratio, meaning the width is 1.5 times (3 divided by 2) larger than the height.
For reference, a Canon 5D Mark IV produces full-resolution images at 6,720 x 4,480 pixels. By multiplying the height (4,480 pixels) by 1.5, you arrive at the width (6,720 pixels). A useful way to visualize aspect ratios is by comparing them to a 1:1 (square) ratio—the wider the image, the higher the first number will be when divided by the second.
It’s important to remember that aspect ratios define proportions but do not determine resolution (the number of pixels in an image). Two cameras may have the same aspect ratio but different resolutions depending on pixel count. Simply put, aspect ratio describes an image’s shape, not its clarity or detail.
Common Aspect Ratios in Photography
(Note: Aspect ratios are typically written as width:height. When switching from landscape to portrait orientation, the numbers are reversed—for example, a 3:2 landscape image becomes 2:3 in portrait.)
3:2
A 3:2 aspect ratio photo.
As mentioned earlier, most DSLR and mirrorless cameras have sensors that capture images in a 3:2 aspect ratio. This standard originates from 35mm film cameras, which produce images measuring 36mm x 24mm—resulting in the same 3:2 ratio. (Yes, those fraction-reducing skills from elementary school are paying off!)
Both full-frame and APS-C (crop) sensors maintain this 3:2 aspect ratio, despite their size differences. While full-frame sensors mirror the traditional 36mm x 24mm film format, APS-C sensors are more compact—typically around 24mm x 16mm, though exact dimensions vary slightly by manufacturer.
1:1
A 1:1 aspect ratio photo.
A 1:1 aspect ratio means the width and height of an image are equal, creating a perfect square. This format is commonly available on smartphone cameras and is also frequently used in medium-format cameras. Many medium-format film cameras support 120 film, which often produces images in a 1:1 ratio, typically around 56mm x 56mm.
Social media platforms, particularly Instagram, once required all posts to follow a 1:1 aspect ratio—hence the dedicated square setting on many smartphone cameras. However, Instagram has since expanded its format options, allowing everything from horizontal images with a 1.91:1 aspect ratio to vertical images with a 4:5 ratio. Many photographers still hope for even more flexibility, especially for sharing panoramic or ultra-wide landscape images.
4:3
A 4:3 aspect ratio photo.
As the name suggests, Micro Four Thirds cameras use a 4:3 aspect ratio. This format is also common in most point-and-shoot cameras and some medium-format cameras. While modern smartphones offer multiple aspect ratio options, 4:3 remains the default for most devices.
5:4
A 5:4 aspect ratio photo.
The 5:4 aspect ratio is most commonly found in medium- and large-format cameras. It aligns well with the standard 8″ x 10″ print size, making it a popular choice for professional prints and fine art photography.
3:1
A 3:1 aspect ratio photo.
With its significantly greater width than height, the 3:1 aspect ratio is widely used in panoramic photography, making it ideal for capturing expansive landscapes and wide-format compositions.
The 3:1 aspect ratio is popular for panoramic photographs.
Aspect Ratios in Film
While this article primarily focuses on aspect ratios in photography, it’s worth noting that film and video formats often use different aspect ratios. Some do overlap—for instance, standard-definition video follows a 4:3 aspect ratio. However, high-definition video has a standard aspect ratio of 16:9, while the most common cinema formats are 1.85:1 and 2.39:1. IMAX films typically use a 1.43:1 aspect ratio but can also be presented in 1.9:1.
This brings us back to the excitement around Oppenheimer. The film was shot on 70mm IMAX film, with reels weighing over 600 pounds. To experience the “true” version, viewers must visit select theaters capable of displaying the full IMAX 1.43:1 and 2.20:1 aspect ratios without cropping. According to the film’s official website, Oppenheimer was shot entirely on analog film and alternates between 2.20:1 and 1.43:1 in theaters equipped for IMAX projection. In most standard cinemas, however, the film is cropped to fit the industry-standard 1.85:1 or 2.39:1 aspect ratios. While this cropping results in only a minor difference, many film enthusiasts prefer to see the movie in its intended format—hence the ongoing discussions about the best way to watch it.
Oppenheimer stills showing the relative sizes of IMAX 70mm and 70mm film compared to a 35mm film frame, and the aspect ratios of each.
Changing Your Aspect Ratio
Most modern digital cameras allow users to adjust the aspect ratio directly in-camera. To change this setting, refer to your camera’s manual or look up instructions online. Many DSLR and mirrorless cameras offer multiple aspect ratio options, including 3:2, 4:3, 16:9, and 1:1, which can be selected through the camera’s menu settings.
Changing the aspect ratio in the Camera app settings of an iPhone.
Shooting and Cropping for Aspect Ratios
Many photographers prefer to shoot using their camera’s default aspect ratio—typically 3:2 for DSLR and mirrorless cameras—and crop later if needed. Most post-processing software includes an Aspect or Aspect Ratio menu for easy adjustments. In Lightroom, for instance, this feature is accessible through the Crop tool, where users can select common aspect ratios or enter a custom ratio for more precise framing.
Aspect Ratios Can Be Challenging
Printing Considerations
Just as film enthusiasts want to experience Oppenheimer in its intended format, photographers often face challenges when printing images in different aspect ratios. For example, a 2:3 aspect ratio image fits perfectly on a 4” x 6” print, but won’t align exactly with 8” x 10”, 11” x 14”, or 16” x 20” paper sizes. To accommodate these differences, photographers must either:
- Crop the image to match the paper’s aspect ratio.
- Print the full image at a smaller size, leaving a border around it.
Borders can be a point of debate among photographers. Some appreciate them for easier handling, mounting, and framing, while others dislike them for making the final image size less predictable, particularly when printing for clients. While the paper may measure 16” x 20”, a 2:3 image with borders will be smaller than the full sheet.
Ultimately, there are always workarounds for aspect ratio mismatches, but photographers must decide which approach best suits their needs—and, if applicable, their clients’ preferences.
A 4:3 aspect ratio photo.
Displays and Websites
In today’s digital world, display sizes vary widely. From ultrawide monitors with 21:9 or even 32:9 aspect ratios to constantly evolving smartphone screen dimensions, keeping up with the different ways people view content can be challenging.
For digital displays and websites, achieving a perfectly fitted image often requires cropping to match the specific aspect ratio of the display or platform. Instead of relying on automated cropping by a website builder or display settings, it’s often better to manually adjust the aspect ratio to ensure optimal framing and composition.
Many website builders and digital platforms also allow images to be inserted as-is, adding borders or empty space if the aspect ratio doesn’t match. This approach can preserve the full image but may affect the overall presentation. Understanding aspect ratios helps photographers and designers make the best choices for displaying their work across different screens.
A 2:3 aspect ratio portrait photograph.
Conclusion
Understanding aspect ratios is essential in photography, especially if you plan to print or share your work. An aspect ratio simply describes the relationship between an image’s width and height—it does not determine resolution or actual size.
Experimenting with different aspect ratios can help you refine your artistic style. You may find that you prefer wider formats for landscapes or square ratios for portraits, leading you to explore new creative possibilities. Some photographers even develop a preference for aspect ratios commonly used in medium-format cameras, influencing their approach to photography.
No matter how you choose to experiment, being mindful of aspect ratios will enhance your ability to compose, present, and share images effectively—ensuring they look their best across different mediums and formats.
