What is Image Resolution and Aspect Ratio?

What is Image Resolution and Aspect Ratio?

Photo: Freepik.com
Photo: Freepik.com

Image resolution is one of thee most important factors that determine the overall quality of your print project. The higher resolution, the sharper the image will be when resized or printed. Lower resolution images appear fuzzy, jagged, or blurry.

The settings used during the original “capture” of an image determine its base resolution. Resolution can only be improved by decreasing the image size, or by recapturing the image at a higher quality setting.

What is image resolution?

The term resolution refers to the number of pixels (or dots) within an image. Resolution is often identified by the width and height of the image, or the total number of pixels within the image.

Example: an image that is 1600 pixels wide and 2000 high (1600×2000) contains 3,200,000 pixels (3.2 Megapixels).

What is dpi?

DPI, or dots per inch, defines the physical size an image will be when printed. If you plan on printing your photos you can use this simple formula to determine the maximum photo size you will be able to print.

Example: to print a 6” wide by 4” tall photo your image should have a resolution of 1800×1200 @ 300dpi (2.16 Megapixel). 300dpi – 6” = 1800pixels, 4” = 1200pixels.

All print projects are designed at a resolution of 300dpi or greater, your photos and logos should be at this resolution. The standard dpi for on-screen images is 72dpi; use this dpi setting when resizing your images for use on websites.

DPI is for print media

In cases where Images are used for web and on-screen use the dpi measurement of an image does not matter, images are sized by pixels.

Example: two images with a size of 300×300 pixels with resolutions of 300dpi (1”x1”) or 100dpi (3”x3”), either image would render the same size on screen.

What is aspect ratio?

The aspect ratio of an image is the ratio of the image width divided by the image height and are mathematically expressed as x:y. For example, an image 1867 pixels wide by 1400 pixels tall will have the same aspect ratio as an image 448 pixels wide by 336 pixels tall (1.33:1 or 4:3).

  • In still camera photography the most common aspect ratios are 4:3 (1.33) and 3:2 (1.5).
  • The five common aspect ratios are 4:3, 3:2, 16:9, 1.85:1, 2.39:1.
  • The 4:3 ratio is the original ratio used in standard television broadcasting.
  • The 16:9 (1.77) ratio is the international format of HDTV, non-HD digital television and analog widescreen.

Common print sizes for photographs in the United States include:

  • 6×4” (1.5)
  • 7×5” (1.4)
  • 5×4” and 10×8” (1.25)
  • 14×11” (1.27)

Large format cameras typically use one of these aspect ratios.