Now, watch carefully as I increase the resolution of the image without messing with the number of pixels. If I were to try printing the thing at its current resolution, it’d be more than 43.5 inches by 32.5 inches… INCHES! Note the honking big physical dimensions of this image. Remember these numbers for a few seconds.ģ.

Note the pixel dimensions shown in the upper portion of the Image Size dialog: 3136×2352 (also circled in red). At the bottom of the document window, you can see that the file is indeed large-it’s 21 MB (circled in red).Ģ. There are several important things to note in this screenshot:ġ. Does this mean my photo is of low-quality and unsuitable for print? Not at all. I popped open the photo in Photoshop and took a peek at its Image Size dialog to find that it was 3136×2352 pixels, but only 72 ppi. I thought this shot might make good stock photography so I took it on a high-quality setting so I’d have sufficient pixel data for printing.

You’re going to encounter 72 dpi files that need to be printed, and because you’ll need to resize that image, you need to understand how to change one without changing the other.įor example, let’s take a photo from a high-quality digital camera (an Olympus Evolt E-330 to be exact). As you now know, this is true when it comes to print but not so much any other time.īecause any file-the same file-can be measured at 72, 300, or 3000 dpi, its pixel dimensions are what matters most, not its resolution. We’ve been told to pay attention to its resolution instead. That’s a pixel, and for the most part, creative types have been brainwashed not to pay attention to the number of pixels an image contains. I won’t bore you to tears with a dissertation on how the smallest picture element of any digital image is called a pixel and how images are displayed in tiny blocks (also referred to as dots) of color that together form an entire image (or maybe I just did). If someone else is printing it for you, ask them what dpi they need. If it’s your own printer, run a few tests. While the current crop of consumer-level inkjets does a fine job at 225-250 dpi, a professional service bureau may require 300+. So how much resolution do you need to make a gorgeous print? It depends on the printer. Your monitor just doesn’t care: A 72-dpi image will look exactly the same as a 3000 dpi image. That’s right, it doesn’t mean a hill of beans until that image is headed for a printer because only a printer can do anything with the resolution measurement. Conversely, the lower the resolution, the more loosely those pixels are packed and the larger the image can be physically-though it loses definition and the print will look extremely undesirable and, well, chunky.īecause our monitors can only display a certain amount of information that our eyeballs/brains can process, resolution matters only to printing devices. The closer the pixels are packed together, the smaller the image will be physically when printed. The way resolution affects an image is thus: For a given number of pixels in the width or height of an image, the higher the resolution, the closer the printer packs those pixels together in order to make a beautifully smooth and sharp print. It’s a measurement used for printing (hence the phrase “of printed length”) and it’s usually stated in pixels per inch (ppi-used when referencing screen images) or dots per inch (dpi-used in printing because printers print dots). Simply put, image resolution is the number of pixels displayed per unit of printed length in an image. First, let’s chat briefly about resolution in general. We’ll discuss the difference between upsampling-a rather evil practice of increasing the resolution (and thereby the number of pixels) in order to make the image larger than it originally was-and changing the resolution of an image without changing pixel data. Today we’re going to talk about the relationship between resolution and pixels, and what it means to you. You’d be shocked at the number of brilliant designers who don’t know how to change an image from 72 dpi to 300 dpi-without turning it into a pile of pixel mush. Possibly one of the most confusing aspects of dealing with digital imagery is resolution-specifically, what it really is and how changing it affects an image.

Make image smaller on photoshop