Blur Tool in Photoshop: The What, How, and Why

Photoshop is a great program to use for just about everything. It allows photographers to touch up their photos, graphic designers to create images and Facebook meme lovers to design their own internet sensations. The extensive selections of tools in Photoshop can be daunting for novice users; there are a zillion buttons to push and each button has its own subset of tools. Don’t let it confuse you. There are guides like this one, courses like Photoshop Tools, and support forums to help you navigate the program.

The blur tool is one of the most widely used functions in Photoshop and it has an array of capabilities. Here, I’ll go over what the tool is, how to customize it for your project and a few practical applications of “the blur”.

The blur tool is used to – you guessed it – blur images. However, this tool gives you the flexibility to blur certain sections of a photo, like the background, while leaving the foreground in focus. It helps create the sense of movement in a photo when the picture was taken stationary. You can use the blur tool to highlight an object in a photo by blurring the other objects in the photo. This tool is also used when touching up skin in photos. It helps smooth out the edges and blemishes without “coloring” them in. It’s a more natural approach. For more about skin touch-ups read Airbrush in Photoshop.

The blur tool icon looks like a rain drop. It’s on the tool panel which is defaulted to the left side of your Photoshop screen. If you right click it, you’ll be presented with the smudge tool, the sharpen tool and the blur tool. We’re focusing on blur in this article. If you’re new to Photoshop, take this Photoshop 101 course.

The long and short of it is: the blur tool blurs your image. When you click on the blur tool your cursor turns into a circle and it acts as a paint brush. You just paint over the part of the image you wish to blur. You can adjust the size of the brush and the hardness (how much blur you want) at the top of your screen. See an example below, the top train is the original, a section of the bottom train has been blurred.

Within the blur toolbox (which you can access by going to Filter>Blur) you have several more blur options including: Average, Blur More, Box, Gaussian, Motion, Radial, Smart, Surface and Lens. For any of these filters you can apply the blur to the whole image, or sections of the image as discussed in a moment. But first, what do these blur tools do?

Note that all of these tools can be used in conjunction to create the perfectly blurred image. For example, you can use the “blur more” tool and then use the “Gaussian blur” tool to fine tune the original blur.

Most of the blur options let you adjust the radius and threshold of the blur. The radius blurs pixels at a certain distance away; and the threshold indicates which type of pixels you want to see blur.

Average blur is just that, average. If you want your selection to just be a little blurry (barely noticeable) – this will do it.

Blur More will blur the picture more than the average blur will.

Box Blur blurs all nearby-pixels together for a smooth, line-free blur. You can adjust the blur by changing the radius in the box blur pop-up box.

Gaussian Blur allows you to fine tune the blur.

Motion Blur puts your image into motion like if you took a photo of a biker, or a passing train. See the tutorial at the end of this article on how to create a background in motion while keeping the object clear.

Radial Blur puts a spin to your blur, literally. It makes it look trippy, like you’re going into a vortex or something. You can adjust the spin with the radius button.

Smart Blur lets you blur with precision. You can blend certain pixels together if you’d like to.

Surface Blur makes the whole picture seem a little faded or distant. You can adjust the radius and threshold settings to make it exactly how you want.

Lens Blur allows you to apply different blur lenses to your picture. You can choose from radius, blade curvature, rotation, brightness, threshold and noise (what gives it that static look).

Okay, now that you know what the blur tool is capable of doing – let’s apply the motion blur to the same picture, but to a specific area of the picture instead of the whole thing.

Example: Dird in Motion

If you haven’t noticed already we’re working with a dird – or a dog-bird. The task at hand is to blur the background so the dird appears to be moving through some kind of mystical green mass. Okay, so this isn’t the most practical of projects but everyone has a soft spot and mine is dirds. Let’s go.

There are some really great artistic tools to let your creativity flow – check it out in the course Photoshop for Artists.

Step 1

Open a photo into Photoshop by going to File>Open and then select your photo.

Step 2

You should see a Layers panel on the bottom right hand of your screen that has a small icon of the image with the word Background next to it. If you don’t see this panel hit F7 and it’ll pop up.

To be able to edit this photo we need to create a duplicate layer over the background image. To create a duplicate layer hit CTRL+J.

Step 3

Okay. Now that you have your new layer it’s time to start blurring. I am going to start off by using the motion blur tool to make the dird look like it’s on the go. To do this, make sure your layer 1 is highlighted in the layers panel and then go to the top of your screen to Filter>Blur>Motion Blur. Adjust the angle and the distance until you are satisfied with the blur. I’ve put my angle at 0 and my distance at 35. Hit OK.

Blurry dird:

Step 4

So the next step is to make the dird not look blurry. We do this by applying a layer mask. Essentially we are going to paint over the dird to say “hey Photoshop, I don’t want this part of my picture to be blurry”. To do this you want to select the icon that looks like a hole in a box at the bottom of your layers panel. You should see a white empty box next to your image in the layer 1 field of your panel.

Step 5

Next on the list is to use the brush tool to “paint” the dird. Painting the dird will make him un-blurry and thus completing this motion blur tutorial. Hit B to activate your brush tool. In the top right corner of your screen you should now see a little box with a number and a circle above it. This is where you will change the size of your brush tool.

For more detailed images, you’ll want to use a smaller brush size and zoom in the picture to make sure you get the edges of the image without running into the background. To zoom in push CTRL and the plus key, to zoom out push CTRL and the minus key. To paint, just click and drag your brush around. You’ll see the image beginning to clear up. If you make a mistake and un-blur the background, it’s okay! You can fix it by hitting CTRL+I which will invert your image, you can use the brush to clean up the background. Click CTRL+I again to revert back to the blurry background image.

And there you have it, motion blurred dird.

You can do similar techniques using all of the different blur tools.For more awesome photography tips in Photoshop check out Photoshop for Photographers.