Motion blurring is a result of camera movement, combined with a slow shutter speed, while tracking a fast-moving object such as a race car, racing motorcycle, a wildlife nature shot, or any other type of action photography.
This Photoshop tutorial is designed to instruct on the use of Photoshop's Motion Blur filter and Radial Blur filter to add the effect of a rapid panning motion, blurring your static looking action photo. This effect can add life, excitement, and drama to an otherwise boring photo that was shot at a high or fast shutter speed.
Using Photoshop's Motion Blur Filter
The first step in this tutorial is to isolate the foreground subject from its background. Using the Polygonal Lasso Tool(L), create a selection of the foreground object.
Technical Note: Don't bother with auto-tracing functions, or the 'Magic Wand Tool (W)' to do the work for you. These tools never produce a good result, especially if your foreground object has similar tonal value to the background you are separating it from. It may take time and patience, but the end result will be realistic and convincing.
Once your selection is made, you will use the Selection Tool's 'Smooth' function (Select>Modify>Smooth) to smooth out any rough edges. Now you will use the 'Feather' command (Select>Feather) to soften the selection by 1 pixel. Copy and past your selection into a new layer, creating an isolated foreground object (above, left).
Now you will 'Command>Shift' click the new foreground layer in the Photoshop Layers Pallet, and use the Select>Inverse command in the menu-bar to reverse the selection. Everything but the foreground object should now be selected. While the selection is active go back to the background layer copy and paste the background into a new layer (above, right). Make sure this new background layer is under the top foreground 'car' layer.
Next you will use Photoshop's Clone Stamp Tool (S), or the Selection Tool (L), to duplicated the background, filling the hole that the foreground object was located in. This does not need to look completely perfect, as the motion blur filter will obscure most of the fine detail.
Now you are ready to add the motion blurring effect using the Photoshop Motion Blur filter (Filter>Blur>Motion Blur...) located in the upper menu-bar. There are two settings in the Motion Blur filter's dialog box - Distance and Angle
Setting the Motion Blur Distance, Angle
The filter's Distance setting controls the length of the blurring effect by number of pixels. Set the distance pixel length so that there is an appropriate amount of motion blurring, without looking artificial.
The filter's Angle setting controls the angle that the blur is oriented in, and the orientation MUST match the approximate angle you would use when panning the camera to track the moving object. Use the dialog bos 'Zoom' window to find a section of roadway, as this is most-likely what you would have been tracking while panning the moving object.
Now that we have added motion to the background, the fast-spinning wheels don't match the speed-blur of the background. We will use Photoshop's Radial Blur filter to add a spinning motion rotation-blur to the wheels, so that they simulate the same slow shutter-speed effect - see: page 2 below.
Page 2: Adding Wheel Motion with the Radial Blur Filter
