Understanding photo resolution and its impact on the quality of the photo


Overview:  a digital photo is actually information. The more information you have, the better the photo. If the information is too little, it affects the quality of the photo.


  1. There are two primary measurements on digital photos.  The first is the size and the second, and more importantly, the resolution.

  2. Resolution governs the size and the quality/sharpness of the photo.

  3. Resolution is expressed in many ways, but primarily in lpi (lines of resolution) and dpi (dots per inch).

  4. Many digital cameras today allow the user to set the size of the image when it is taken.  One of the best settings is 5 megapixels.  You can go much higher but 5 gives you a photo sized for almost any use expect actual posters.

  5. Your ability to adjust these measurements after the photo is taken depends on the program you are using to edit/resize your photos.

  6. For example, on a newer camera set at 10 megapixels, the initial image is set at 180 lpi or dpi and measures more than 30 inches wide.

  7. For MLS and website uses, photos should be changed to 150-to-200 lpi or dpi.

  8. There is usually a click box or the ability to chose “Keep aspect ratios.” Please use this feature.

  9. To keep editing simple, first change the lpi or dpi to 150-to-200, and let the width of the photo adjust to that setting. This ability is usually found under a program menu item named “Image Size.”

  10. However, if you need a specific size, then adjust the photo width AFTER changing the lpi or dpi. The ability to do that is also found under “Image Size.”

  11. Making a low resolution photo wider (and taller) will sometimes result in pixelization, which mean the dots become so large that the image appears out of focus and/or with a large grain.

  12. For those using Macs and want to learn the size of a photo, click on the photo once and then hit Apple key/i.  It will bring up a box with a lot of information about the photo, including its size.

  13. For those using Windows, the Photos app will provided editing options and the size of the photo.