Advertisement

SKIP ADVERTISEMENT

TECH TIP

Why That Digital Photo Print Is Fuzzy

If your pictures look blotchy and out of focus, you likely need to print them at a smaller size or find a version of the photo at a higher resolution.

Q. How can I find out how big I can print a digital photo before it gets blurry? How do I find out the file’s pixels and resolution?

A. The “pixel” (short for picture element) is a tiny segment of visual data and the basic unit of measurement when talking about digital-photo resolution. Rows of pixels create the image. In general, the more pixels per inch (p.p.i), the sharper that image tends to be, thanks to the “higher” resolution.

On a Mac, you can quickly see the pixel dimensions and resolution of an image by selecting its desktop icon and pressing the Command and I keys to open the Info box; Windows users can right-click the icon and look in the Properties box. You can also find the information by opening the image in a photo-editing program.

Image
You can see a photo's file size and pixel dimensions in the file's Info or Properties box. The top image has a lower resolution than the version below it. Low-resolution photos typically look fuzzy when printed too large.Credit...The New York Times

Printers measure resolution in (ink) dots per inch, or d.p.i. While pixels-per-inch and dots-per-inch are not the same, the higher the d.p.i., the finer the quality of the printed photo. A standard resolution for printed photos is 300 d.p.i.

When preparing to print a digital picture, consider the size of the print itself, like 4 inches by 6 inches. The ScanTips site has a calculator at www.scantips.com/calc.html that you can use to convert pixel dimensions for printing at 300 d.p.i. on a specific paper size.

For a rule of thumb, if you want to know the maximum size that a file can be printed and maintain its visual quality, divide its pixel dimensions by 300. A picture with pixel dimensions of 640 pixels wide by 480 pixels high will print at slightly more than 2 inches wide by 1.6 inches high, while an image with a higher resolution of 3,768 pixels by 2,512 pixels should look fine as a 12-by-8-inch print. Commercial shops for scanning and printing may have their own guidelines, as do many photography websites.


Personal Tech invites questions about computer-based technology to techtip@nytimes.com. This column will answer questions of general interest, but letters cannot be answered individually.

J.D. Biersdorfer has been answering technology questions — in print, on the web, in audio and in video — since 1998. She also writes the Sunday Book Review’s “Applied Reading” column on ebooks and literary apps, among other things. More about J. D. Biersdorfer

A version of this article appears in print on  , Section B, Page 5 of the New York edition with the headline: Why a Digital Photo Can Look Fuzzy. Order Reprints | Today’s Paper | Subscribe

Advertisement

SKIP ADVERTISEMENT