154. Add Motion to an Image Before You Begin  148 About Sharpness
See Also  149 Sharpen an Image
150 Blur an Image to Remove Noise 151 Blur a Background to Create Depth of Field 152 Create a Spin Effect
If you want to add the appearance of background movement to your image, you can use the Motion Blur filter. When you use this filter, you make objects look like they are moving fast. The Motion Blur filter blurs the image in the direction you specify. You can specify an Angle between 360 and 360 degrees. You can also control the "length" of the motion blur: The higher you set the Distance value, the more pixels are blurred to create the motion effect. You can apply the Motion Blur filter to a selection or to the entire layer. A good approach to using the filter is to copy the Background layer and apply the filter to the Background layer. Then you can erase the top layer (the copied layer) at the locations where you want the motion to appear. 1. | Create a Duplicate Layer
Open the image you want to adjust in the Editor in Standard Edit mode and save it in Photoshop (*.psd) format. If it's not already showing, display the Layers palette by selecting Window, Layers. In the Layers palette, select the Background layer and then choose Layer, Duplicate Layer from the menu bar to duplicate the selected layer.
| 2. | Apply the Motion Blur Filter
In the Layers palette, choose the Background layer. Select Filter, Blur, Motion Blur from the menu bar to display the Motion Blur dialog box. Enable the Preview check box.
In the Angle field, indicate the number of degrees for the motion angle. You can see the motion direction on the circular button to the right of the Angle field. You can also change the Angle by clicking the button and dragging its handleliterally twisting it like an old TV channel changerin the direction you want the motion.
In the Distance field, indicate the number of pixels over which the blur effect is to be applied. The larger the value in the Distance field, the longer the blur streak will be. Watch the preview window in the dialog box to get an idea how your settings will affect your image.
Click OK to close the Motion Blur dialog box and apply the blur settings to the Background layer. The blurred layer is not visible at this point because the nonblurred layer is on top.
TIP  | Use the and + buttons under the preview window on the Motion Blur dialog box to change the zoom settings of the preview. |
| 3. | Erase Portions to Add Motion Blur
Select the Eraser tool from the Toolbox. On the Options bar, set the Opacity of the tool to 100%, and adjust the Size field to match the part of the background you want to blur.
In the Layers palette, select the unblurred Background copy layer. Use the Eraser tool to erase the areas you want to blur. Where you apply the Eraser tool, the unblurred area is erased, revealing the blurred Background layer underneath.
| 4. | View the Result
When you're satisfied with the result, make any other changes you want and save the PSD file. Then resave the result in JPEG or TIFF format, leaving your PSD image with its layers intact so that you can return at a later time to make new adjustments.
In this example, I used the Motion Blur filter to create a motion effect for the vehicle behind the giraffe. Because the movement of the vehicle was fairly horizontal, I kept the Angle setting at 0. I increased the Distance setting to 283 pixels to create a fairly large amount of motion.
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