How to Apply Blur to a Specific Target in Photoshop

Use layers to apply a motion blur to one object in a photo while leaving the rest of the image unafffected.

When adding a blur to an image, sometimes it's preferable to add a blur to one target area but not another. There are two ways to achieve this in Photoshop. First, you can isolate the target on its own layer, then apply any of the blur filters to that layer without affecting the rest of the image. This is useful for applying a specific type of blur, like Motion Blur, to a target. The second way is to use the Blur tool. This tool allows you to control what is blurred and what is not without having to create an additional layer.

Instructions

Using Blur Filters

1. Launch Photoshop. Press “Ctrl-O” on the keyboard and select a photo to work on in the navigation window. Click “Open.”

2. Select the “Background” layer in the Layers Panel and drag it onto the “New Layer” button at the bottom of the panel. This duplicates the layer as “Background Copy.”

3. Zoom in to the area you want to blur. You can zoom by holding the “Ctrl” key down and pressing “+” to zoom in or “-“ to zoom out.

4. Select the “Lasso” from the Toolbox. Drag the Lasso across the object you want to blur until it is encircled. You can also use the “Rectangular Marquee” or “Elliptical Marquee” tool to select objects that are square or elliptical.

5. Click the “Selection” menu, then “Inverse.” Press “Delete.” This deletes everything except your object.

6. Click the “Filter” menu and select “Blur.” A list of eleven blur options is presented. Click on an option. Clicking “Average,” “Blur,” “Blur More,” will apply the blur effect to the layer. Clicking the other options, like “Motion Blur” for example, opens a dialog box that allows you to customize the blur.

Using the Blur Tool

1. Open an image in Photoshop as described above. It is not necessary to have separate layers when using the blur tool.

2. Select the “Blur” tool from the Toolbox. Click the “Brush” menu in the Options Bar at the top of the screen to select a diameter for the tool.

3. Type "50" percent in the “Strength” menu to begin with. The higher the percentage, the stronger the brush will be.

4. Select the “Sample All Layers” option if you want the tool to take all layers into account when blurring the current layer. Deselect this option to restrict blurring only to the current layer.

5. Drag the Blur tool across the object in the image you want to blur. The more you pass over the object, the blurrier it becomes.

References

• Adobe: Photoshop CS5: Layer Basics
• Adobe: Photoshop CS5: Blur Filters
• Adobe: Photoshop CS5: Blur Image Areas