What is Resolution?

When printing large-format graphics, it’s extremely important to always consider the resolution of the photos and images used in the design.

What is resolution? Now that most everything is shot with digital cameras, every picture is made up of little pixels divided into rows and columns. The more pixels there are in a photo, the higher the resolution resulting in a crisper more clear photo. In order to take a photo with high resolution, the camera used must have a large censor to capture the image. Most pocket cameras shoot photos great for your Facebook or Twitter but will NOT produce great photos for large format graphics. A professional camera is required to do so.

This illustration below is a rough example of  “low res”  and “high res”

Resolution

For our purposes, the photo on the left was shot with a pocket camera with a small sensor unable to pick up extreme detail. The photo on the right was shot with a professional camera with a larger sensor able to produce more pixels.  Once a picture is taken, pixels can NOT be added – you’re stuck with the resolution the camera offers. Some software claims to “up-res” your photos, but don’t buy it! The resolution can NOT actually be improved.

So when using photos in your design for larger format graphics, make sure the original photo was taken with a high quality camera that is able to capture the image with LOTS of pixels?

Wait, what about DPI for printing?

Okay, lets pretend we took a picture with a decent digital camera and produced an image with a file size of 1500 pixels x 2280 pixels. This would be way too big for your typical Facebook picture – those usually run about 720 pixels x 480 pixels. But the size may be big enough to print on a small outdoor sign and look pretty good.

DPI stands for  “Dots Per Inch.” This literally means, that for every inch, there are 100 pix. So if we do some quick math remembering that there are 10o pixels per inch with 100 DPI, our image printed on a small sign at full size would be 15 inches x 22.8 inches.

Remember, no matter what, you can NOT increases the quality of an image by adding to the total number of pixels in an image. DPI refers to how many of those pixels are crammed into an inch. So again if we use that 1500 pixel x 2280 pixel image – this time for a newspaper which prints at 300 DPI – the photo at full size would be 5 inches x 7.6 inches on the printed page.

Tips:

– Make sure the image is shot with a quality professional grade digital camera

– Large-Format Printers often, recommend printing at a minimum of 72-100 DPI.

– DPI refers to the amount of pixels crammed into an inch.