An aspect ratio defines the relationship between an image’s width to its height, and the standard motion picture aspect ratio can be traced back to one man: William Kennedy Dickson.

As a staff photographer for Thomas Edison, William Dickson was tasked with utilizing the newly mass-produced flexible film stock that Eastman Kodak was pushing out with Edison’s own kinetoscope. With this 35mm wide film, Dickson settled on an image that was 4 perforations high, creating the soon to be industry standard of 4:3. The 4:3 aspect ratio has since been influencing everything photo related from televisions in the 1950s, 4K UHD, and even digital cameras.

[REWIND: What Is JPEG? JPEG Definition & All You Need To Know About It]

The aspect ratio for still photography will have an impact on your final printed image. If you’re looking to print images at 5×7, 8×10 or 12×16, the 4:3 aspect ratio will be ideal. However, if you are looking at printing 4×6, 12×18, or 20×30 then you want to be shooting at an aspect ratio of 3:2. Even further still is the 4:5 ratio which will print images natively at 8×10, 16×20 and 24×30.

Many digital cameras allow the user to select multiple image aspect ratios in-camera, but of course this is something that can be done in post – provided your composition allows, and then there are some who achieve this through the use of multi-aspect sensors. With all the ratios and print sizes available it can become confusing, which is why we’re featuring Tony Northrup in his recently produced a video that is a neatly put-together introduction to aspect ratios. Is it exciting? No. But worth the time.