If you don't know the difference between image resolution and your New Year's resolution, don't worry! This guide explains different resolutions and what image resolution you should be using for both graphics design and print work, and then shows you how to set the correct Photoshop resolution.
Photoshop: Resolution and You
You may have heard the the term "resolution" tossed around quite a bit in this day in age. TVs have different resolutions, cameras have different resolutions, screens have different resolutions, and even images have different resolutions. But what do all these different resolutions mean to you? What ones should you be using? Inside this article we'll explain the differences, as well as how they can apply to desktop publishing projects, and then finish up with showing you how to set the correct Photoshop resolution.
Digital cameras capture images in a certain resolution, or a set number of pixels. You've heard about megapixels, right? Of course! Megapixels are the number of pixels (in millions) that your camera takes pictures in. Lower quality cameras are between 1-3 megapixels and usually come built in to MP3 players and cellphones. 4-6 megapixels are your basic point and shoot models. 7 and up are usually considered not too bad, even though it isn't uncommon to see cameras upwards of 12-13 megapixels in the price range of the average photo enthusiast. The higher the megapixels, the higher the quality of image. More information on camera resolution and the importance of megapixels can be found here: What are Megapixels & How Many Do I Need in a Digital Camera?
Your computer screen (or monitor, rather) has a resolution. Basically, whatever the resolution is, it defines how many pixels are visible on screen at any one time. Increasing your monitor resolution say, from 800x600 to 1024x768, allots a larger workspace by making each individual pixel smaller. There are dozens of different monitor resolutions, and you should experiment to find the one best for you. More about monitor resolution and how it works can be found here: What is Computer Monitor Resolution?
This is probably the most important resolution to the average desktop publisher. Image resolution can easily be defined as the size of your images individual pixels when you print. But how to visualize this? Easy! Images are made up of pixels, and each pixel can only be a single color. Below is an image of Isabel, and in the top right corner you can see a zoomed in view of the pixels around Isabel's eye.
The smaller the pixels in the images, the more easily they blend, and the less noticeable to the naked eye they appear. Using an image with a low resolution generally makes for a smaller file size. Images on the internet, as well as Photoshop's default resolution, are typically 72PPI (pixels per inch). This is because the standard resolution for a computer monitor is 72PPI as well. However, as with most things computer, there are always slight differences from resolution to resolution and monitor to monitor.
Printwork, however, should use a somewhat higher resolution. The standard is 300PPI, which allows the pixels to blend well to the naked eye. I'm sure you've seen a low resolution image printed out and noticed how grainy it looked. Raising the resolution of your image will fix this. 72PPI for web and 300PPI may be the standard, but there is a little bit of a grey area when looking at these "hard set" numbers. (Example: Anything above 150PPI generally looks pretty nice when printed.)
Setting the Resolution in Photoshop
When you open a new document in Photoshop, you'll see a window that asks what size, canvas color, and resolution you want your image to have. By default, Photoshop selects 72PPI.
The thing is, when creating something in Photoshop, whether you have it set to 72PPI or 300PPI won't make much of a difference when designing. They'll look absolutely identical. Image resolution really only has an impact on printing. So if you're not going to be printing your creation, leave it at the standard 72PPI. You'll keep your file size lower and that's always a good thing.
Note: It is possible to change your image resolution of a photograph or a previously created image in Photoshop by editing the settings in "Image Size" but please keep in mind that while Photoshop is a handy tool, it isn't magic! If you start with a low quality or small image, increasing the resolution will not make it high quality. In fact, it frequently will lower the quality by stretching the image in strange ways.
Picture of Isabel is property of Amber Neely.
Screenshot taken by Amber Neely for demonstration purposes only.