I Don't Care About DPI

It's true ... I don't care about DPI ... and neither should you (most of the time). Consider these recent requests from galleries:

"Save images as jpegs, at 300 DPI."
"Images should be approximately 800 x 600 pixels at 72 DPI."
"Suggested minimums: 800 pixels in either direction at 150 DPI."

If I needed proof that DPI (dots per inch) is greatly misunderstood, here it is. In this article, I'll explain why DPI doesn't apply to much of what you do with your digital images.

The DPI Myth
Without getting into a long history lesson, the smallest unit of measure in print typography is a point, and there are approximately 72 points per inch. Programmers arbitrarily chose 72 pixels per inch (PPI), and later, 96 PPI, as the basis for calculating different font sizes on a computer screen.

Thus, the myth of 72 PPI was born. And when desktop printers came along with 300 dots per inch, the concepts of PPI and DPI merged into a confusing mess.

DPI Doesn't Matter
Simply put, PPI and DPI don't apply to the display of digital images. A computer screen knows only about pixels, not inches. Each pixel in an image is displayed as one pixel on the screen. The resolution of an image, therefore, is determined by the total number of pixels in it, not by the PPI or DPI. An image will look the same whether it was saved at 72 DPI or 300 DPI.

Don't believe me? Examine these two images. Both have the same number of pixels, but one was saved at 72 DPI and the other at 300 DPI. Click on each one to view it larger. See any difference? You shouldn't, because the DPI doesn't change how the image looks on the screen.

... Except For Printing
Yet the myth lives on. The standard resolution for images on the Internet is widely quoted as 72 DPI. The resolution for desktop printers is often 300 DPI. Bigger is better. So if you want a high resolution image, ask for it at 300 DPI ... right? Well, no, unless you're going to print it.

The DPI only matters for an image that will be printed. Your image editing software uses the DPI to show you the size when printed. Otherwise, you can ignore DPI for images that are displayed on a screen because they will look the same at any DPI.

So if DPI doesn't matter for these images, then what should you care about? I'll answer that question in my next article.

And click here to learn more about resolution in the Learning Center at ShootMyArt.com™.

(The artwork "Lilies" is used by permission of Candace Law © 2001.)

Welcome to ShootMyArt!

Welcome! This begins an occasional series of articles with commentary and insights for visual artists and galleries about the digital imaging of artwork.

Drinking From A Fire Hose
In my experience working with clients and giving seminars, I find the new technologies and terminology around digital imaging both excite and challenge those who create artwork and those who promote and sell it. There is a tremendous thirst for knowledge and understanding, accompanied by much confusion and frustration, as members of the visual arts community embrace the "digital age".

Although there are many resources and a huge amount of information available on the Internet and from other sources, it is a bit like taking a drink of water from a fire hose. Where do you begin? What is most important for you to understand? How do you sort through the sometimes contradictory advice? Can you ever hope to make sense of it all?

How I'll Help
At the risk of adding to the information overload, my goals in writing these articles are two-fold.

The first is to bring some much-needed clarity to the resources and information available to visual artists. I want to enable you to have high-quality digital images of your artwork ... whether you photograph the artwork yourself or use the services of a professional photographer. So I will sort through the clutter and tell you what is important to know and why it matters. Once you begin to understand the key concepts, the remaining pieces of the puzzle will fall into place.

The second goal is to help gallery and exhibition directors better understand how to use digital images for juried shows and in promoting the visual arts. There are some key concepts here, too, that once mastered will improve your collaboration with artists.

In future articles, I'll explain some of the aspects of digital imaging that confound artists and gallery directors, "bust" a few myths about digital images, and provide examples of "best practices" that will help you make it through the transition to digital successfully.

Add Your Comments
I welcome your comments and responses from your own experiences, as well as questions you would like me to address in future articles. You can post comments directly to any article for other readers to see and add their comments, or send me an email at Blog@ShootMyArt.com.

Also, be sure to check out the resources available at ShootMyArt.com™.