Printing your travel photos: PPI vs. DPI

While these days, most travelers display their photos online instead of in the photo albums of the past, many travelers still print more than a few images to keep and show off their travel memories. Some even hang prints of their travels on the walls of their home.

Unfortunately, many travelers, like other photographers, are often confused about sizing their images for printing because countless photographers incorrectly use the terms, PPI (pixels per inch) and DPI (dots per inch) interchangeably.

PPI and DPI are not at all the same, and they are independent of each other.

DSLR Purchasing: APS-C vs. Full Size Sensor?

DSLR's sensors are essentially digital “film.” The sensor is the camera's electronic device which captures images.

Sensors contain millions of “photosites,” essentially buckets which capture the light coming through the DSLR's lens. The light is converted to an electric signal which gets measured, optimized, and converted to a digital image by the DSLR's processor.

The size of the buckets (photosites) is important to the sensor's sensitivity and its ability to accurately gather light in a variety of lighting conditions. Bigger buckets are better than smaller ones, because more light can be stored in them, without getting over-filled. Bigger buckets have a lesser tendency to impart noise into the image.