Earlier this month, our own Kelsey Ó Ciardha penned an informative piece about file types entitled, “.WHAT? Image File Formats Explained.” If you haven’t read it, head on over to here and check it out. I’ll wait.
Great, isn’t it? I love the part about PDFs, and I found her description of the EPS to be quite Dickensian, wouldn’t you agree? As I read through the section on JPGs, it brought to mind a similar principle we sometimes find ourselves needing to explain: image resolution. Image resolution is an often misunderstood concept, and for good reason. With super high-quality screens becoming increasingly more ubiquitous, and the desire for printed pieces dwindling, there’s less of a need to understand the roles and purpose of image resolution. Couple that with video becoming a much more attainable medium, and you’ve got a situation where a diverse array of professionals are regularly operating in a realm of sophisticated technology without having obtained a proper understanding of capabilities and limitations. The world of technology is a constantly shifting system of standards, so it’s easy to understand why some people have a hard time keeping up.
And, really, that’s OK. It’s the job of people like me to bring that understanding to table. Still, it’s good to be armed with information.
The resolution of an image can vary to such a great degree, and we need to consider a lot of things when choosing or working with an image. But let’s start at the beginning: what exactly does “image resolution” mean? When an image is captured, whether it’s a still image, a video, on film, or digital, image resolution denotes the detail held within that image.
The higher the resolution, the greater the detail.
In the interest of keeping your interest, let’s discuss resolution in terms of still digital imagery, like a photo taken with your iPhone. We could get cozy and wax nostalgic about the many types of film photography and videography, beginning with the inception of the media itself, but, seriously, like, who even has time for that?
Imagine you’re at an Adele concert and you pull out your iPhone to snap a pic because she’s looking absolutely majestic and your vision is all blurry because you’re crying sparkly tears of joy. Later that night as you’re lying, sleepless, in a suspended state of clarity, thinking, If everyone would just listen to Adele, there’d be no more war and the world would be so, so peaceful, you grab your phone and look at the photo you took earlier. You zoom in to get a closer look. At a certain point, as you’re zooming closer to that angelic face, you notice the quality of the image begins to degrade. You keep zooming. Suddenly the crisp details are disappearing and fuzzy splotches are taking over Adele’s cherub-like features. You zoom further, searching for answers to life’s biggest questions, but the once-beautiful photo has been reduced to simple blocks of color. So you shut off your phone and stare at the ceiling until morning.
The resolution of that image, determined by the quality of your phone’s camera, is fixed once the image has been recorded. It is made up of a set number of pixels, and, although at it’s original size it looks perfect on your phone’s screen, when you zoom in you’re simply getting closer to those pixels. Kind of like when you’re across the street from an Adele poster and she looks so perfect, so you run over to look at it from an inch away and you realize she’s just made up of a whole bunch of little printed color dots. (For more on printed color dots, check out our earlier post on color.) The physical size increases as you zoom; the number of pixels does not. Eventually, if you increase the size large enough, you get to the point where you see the individual pixels.
If you have access to photo manipulation software, like Photoshop, you might feel inclined to make small, good quality photos larger. But the moment you begin to make that image physically larger, you damage the quality. This is because there are no more pixels available to increase the quality of the image along with the size. You can’t add pixels to a photo once it’s been taken. You can only start over, by taking a larger, higher-resolution photo. You can, however, decrease the size all you want without losing quality. Have an image-size-decreasing party, if you like.
One more thing to take into consideration when trying to understand image resolution: the resolution of the screen itself can vary from one model, brand, or device to another. Cheeky, I know. So, an image that has a fixed resolution will, in some cases, actually look different depending on what you’re using to view it. And don’t even get me started on Retina and high DPI displays.
Here’s a good rule of thumb: if you’ve got a picture you love and you really want to use it to fill the screen of a landing page on your new website, but it’s size is only 100px by 100px and its resolution is 72ppi—you’re out of luck, friend. Any good quality in that image will disappear when you try to increase to that larger size. On the flip side, if you have a gigantic image that’s 300ppi and its dimensions are weighing it at 4000px by 4000px, then do it to it, chief. Same goes for a still from a video. It’s tempting to want to grab a screenshot from a video to use on your website or brochure. But do your best to resist that temptation. Video information is recorded with a whole different set of standards, and, speaking in terms of still imagery, it falls into that 72ppi category. And remember: this stuff is confusing and constantly changing. But fear not! We are always on the case. OK, back to listening to Adele.
Words About Pictures (WAP!) is an ongoing blog post series designed to help our clients (that’s you!) better understand the many creative quirks or qualms they might encounter during a project.