Pixels And Dots Per Square Inch Explained And Compared

If you are a budding photographer, there are a number of terms used in digital photography that you should understand. One of the main areas of confusion is the difference between PPI and DPI. The reason why there is often uncertainty about these two acronyms is that DPI (dots per square inch) is a somewhat outdated term that is often applied to both a digital image's resolution and size, whereas PPI (pixels per inch) has only been adopted fairly recently and is more specific. Having the two terms explained clearly is important if you are serious about developing your photography skills.

PPI is the easiest of these two terms to understand. It relates to the number of pixels per square inch that are present in an image. The PPI can impact a photo's print size as well as the quality of the output. If there are too few pixels in each square inch, the image will appear jagged and out of focus.

PPI primarily affects the print size of photographs. It is important to understand what size print would be suitable in relation to the PPI that exists. The total number of pixels present in an image would dictate the maximum dimensions the picture can be printed at without suffering a drop in quality. Most professional photographers recommend that three hundred PPI be used at the minimum.

DPI is a different type of terminology, basically it is used in relation to how the image is actually printed. Most printers that are common today utilize dots to produce two dimensional images. Each pixel that is printed is made up of a different colored ink, typically cyan, magenta, black, and yellow. As only these four colors are available, the printer needs to mix the inks to render the correct colors in an image.

Each pixel is made of of tiny dots, or sub-pixels. Because of this the greater the DPI, the better the overall tonality of a printed image. What's more, with a high DPI, the colors appear bolder and smoother. On the downside, a high DPI requires more ink to be used and the print job to be performed slower.

If you are primarily focused on displaying images online, you do not have to be concerned about DPI, focus on PPI. On the other hand, if you want to print out a selection of your best photographs, DPI is an important dynamic to be aware of. In either case, PPI and DPI explained and defined will improve your print quality.