One of the common questions asked of us at FinerWorks.com is, “How many pixels do I need for printing photos?”
If you are a non-professional, or just getting started, you may be confused about the concept of pixels and image resolution. First it’s important to understand the terminology that relates to image size and resolution: PPI, DPI, and Megapixels.
Pixels Per Inch (ppi) – A measurement of image resolution that defines the size an image will print. The higher the ppi value, the better quality print you will get–but only up to a point. 300ppi is generally considered the point of diminishing returns when it comes to ink jet printing of digital photos.
Dots Per Inch (dpi)- A measurement of printer resolution that defines how many dots of ink are placed on the page when the image is printed. Today’s photo-quality ink jet printers have dpi resolution in the thousands (1200 to 4800 dpi) and will give you acceptable quality photo prints of images with 140-200 ppi resolution, and high quality prints of images with 200-300 ppi resolution.
Megapixels (MP) – One million pixels, though this number is often rounded when describing digital camera resolution.
When determining how many pixels you need, it all depends on how you will be using the photo and what size print you want. Take advantage of the guidelines below to help you determine how many pixels you need for printing standard size photos through an online printing service like FinerWorks.com.
5 MP = 2592 x 1944 pixels
High Quality: 10 x 13 inches
Acceptable Quality: 13 x 19 inches
4 MP = 2272 x 1704 pixels
High Quality: 9 x 12 inches
Acceptable Quality: 12 x 16 inches
3 MP = 2048 x 1536 pixels
High Quality: 8 x 10 inches
Acceptable Quality: 10 x 13 inches
2 MP = 1600 x 1200 pixels
High Quality: 4 x 6 inches, 5 x 7 inches
Acceptable Quality: 8 x 10 inches
Greater than 5 megapixels
Today very few cameras shoot less than this so the good news is you can usually print very big. As a standard rule with a 6 mp camera you can get pretty good prints as large as 20×30 so if your camera is shooting in the 8 MP ranage or higher you can get some very nice large format prints. Still, there are times when higher megapixels can prove to be helpful. In situations where images need to be aggressively cropped, you won’t have to worry so much about losing image quality. Just keep in mind that the higher the MP the larger the file, and that means less hard drive space.