A little lesson on resolution
Technology | 23 August 2010

A little lesson on resolution

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I was walking the dog today and thinking about how exciting it is that more and more people are using the technology they have available to them to create and share digital images and video. Then I got depressed thinking about how despite having access to more and more technology, not many people understand some of the basic concepts of digital imagery. Clearly, I’m easily depressed. The main concept that I don’t think most people outside of the design/art/education field understand is that of resolution.

As an adjunct instructor (I don’t meant to brag, really) of electronic media and foundation level computer classes, I lecture for about 3 hours each semester to every class on resolution. I somehow make up for this painstakingly meticulous process by watching funny YouTube videos afterwards. Understanding what pixel resolution really is and how to manipulate and manage it is an extremely important tool for artists and designers, but even more so for amateur photographers and also, my Mom – who continues to print images directly from Facebook.

Resolution Myth #1: Low Resolution = Bad Quality

This idea could not be more wrong. And yet, people like to say “oh, the resolution is too low” as if that’s the same as “oh, that’s just a crappy picture”. Every image I have posted on this blog so far has been set at a low resolution, because screens (and therefore the interwebs and its browsers) don’t NEED a lot of information. Screen resolution requires the smallest amount of pixels (72 pixels for every inch of the image), so that’s why web graphics and our Facebook images pop up quickly while still looking great! Low resolution can therefore imply low quantity (of pixels that is), but not necessarily low quality.

Resolution Myth #2: Online Images Can’t Be Printed

So the interwebs doesn’t need that much information (again, think quantity of pixels) but we’ve already countered the first myth that low resolution images (e.g. web images) are lower quality. The problem with trying to print most web images is that while screens/the interwebs need a small amount of pixels to show great-looking pictures, desktop printers that you have at home need more information. If you try to print out someone’s picture from Facebook, it’s going to look crappy. But that doesn’t mean that ALL pictures online can’t be printed. It really comes down to the question “how big can I print it?”

Let’s break down some image sizes. The image below is a scan of a painting of my Grandmother; wasn’t she gorgeous?

The ORIGINAL image size breaks down as the following:
Dimensions in inches: 8″ by 10.667″
Dimensions in pixels: 1200 px by 1600 px
Resolution: 150 ppi

For resolution newbies, ppi stands for “pixels per inch”. Learn it, live it!  150 ppi is a good starting point for printing images yourself. You don’t want to go any lower than 150 ppi. So I can print out this image 8″ by 10.667″ and it will look stunning.

General Myth #1: Lady Gaga is Avante-Garde

Now let’s move on to this image I found on the web.

I’ve resized the Lady Gaga image for posting on this blog, of course. Many of my students are crazy-obsessed with Lady Gaga and this is something I’m still trying to figure out… but I digress. If you’d like to get the original image and use it as a wallpaper on your ‘puter, you can find it here.

The ORIGINAL image size breaks down as the following:
Dimensions in inches: 16.667″ by 22.222″
Dimensions in pixels: 1200 px by 1600 px
Resolution: 72 ppi

So the pixel dimensions of both images are the same!! The only thing that differs between these two images – other than taste and personal preference of course – is the inch dimensions and the resolution. What this all basically means is that the Lady Gaga image can be resized to 150 ppi for printing, but in doing that, the inch dimensions much decrease. We can’t print her at the original inch dimensions which were slightly larger than 16″ by 22″.

Resolution is determined by the amount of PIXELS PER INCH; so if we distribute the pixels across fewer inches (e.g. from 16.667″ by 22.222″ to 8″ by 10.667″) we produce a higher resolution. So regardless of the origin of an image, the thing that really matters is the pixel dimensions and not necessarily the original resolution.

So in conclusion, I too cry pink tears over the misuse of the term “low resolution” and dream of a future world in which everyone – including my Mom – will understand how to manage their image resolution correctly! Also, if you’ve managed to find this blog post, I’d be happy to help anyone resize their images – just send me an email.

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