Understanding Image Resolutions

Curious about how we get your image up to wall art size? Well it all has to do with image resolution.

A digital image, just like the image you see on your computer monitor or television, is made up tiny dots called pixels. The term "Resolution", when used to describe a digital camera refers to the size of the digital image the camera produces, and is usually expressed in terms of "megapixels" or how many million pixels it can record in a single image. The number of pixels a camera captures is called the camera's resolution.

For example, a camera that captures 1600 x 1200 pixels produces an image with a resolution of 1.92 million pixels and would be referred to as a 2.0 megapixel camera. You get to 1.92 million pixels by multiplying the vertical and horizontal dimensions. That number is then rounded off to 2 for marketing purposes.

People get confused about how "big" (in inches) a digital image is. To understand digital image size you simply have to understand that pixels are more tightly packed for printing than for display on a computer screen.

Concrete Finish Wall Mural

Computer monitors display images at 72 ppi (pixels per inch), meaning that there are 72 pixels for every 1 inch of linear screen space you see on your screen. Therefore, if you have an image on the screen that is 720 pixels wide, it will take up 10 inches of linear screen space (72 dpi x 10 inches = 720 pixels). This may look beautiful on the screen, but if you try to print this image on a printer at 72 dpi the result will look extremely choppy and jagged. To get a good looking print from your printer you'll need to print at 300 ppi (pixels per inch), which means that the 10 inches across the screen will be reduced to only 2.4 inches on paper (720 / 300 = 2.4, or 24% of the original 10 inches). The result is a smaller, but much cleaner, image on paper. So a good rule of thumb about how physically big an image will be on paper is that it will be about 25% or one quarter of its size on your screen.

It's important to understand the difference between ppi or pixels per inch and dpi or dots per inch. When we say to print an image at 300ppi a lot of people get confused because their printer is a 1,440 or 2,800 dpi printer.

Let's say for example you have an image that is 1200 x 1200 pixels and you're going to print that image on a 2,800 dpi printer. It would take a screen 16.6 inches wide to display the image at full size.

1,200 pixels ÷ 72ppi = 16.6 inches

On paper that same image would be 4 inches wide.

1,200 pixels ÷ 300ppi = 4 inches

Each pixel in that image will be made up of 9 ink droplets on the paper using a 2,800 dpi printer.

2,800 dots per inch ÷ 300 pixels per inch = 9.3 droplets

  • Mar 30, 2017
  • Category: News
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