152. Create a Spin Effect
Before You Begin
70 About Making Selections
107 Crop a Portion of an Image
150 Blur an Image to Remove Noise
153 Soften Selected Details
154 Add Motion to an Image
One method of blurring the background is to create a spinning effect using the Radial Blur filter. With this filter, you can create two different effects: a Zoom or a Spin. With the Zoom option, your selected region is given the effect of the camera lens being zoomed-in fast during exposure. The Spin option has a circular whirlpool appearance, like rotating the whole camera along the axis of its own lens during exposure.
There are probably very few photos ever produced in the world that would benefit from being spun around in their entirety by the Spin option of the Radial Blur filter. In practice, you would use it to dress up a subject, to place that subject in imaginary space and spin it around. So, when you use this filter, make sure that the subject of the image is not affected by it. In this example, we'll create a copy layer of the background surrounding the subject and then spin that layer around in space exclusively.
Center Subject in the Image
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.
When you don't have an active selection, the Radial Blur filter performs its magic on the entire layer. For this technique to work accurately, the subject you're isolating should be in the general center of the image. (In a moment, her entire world will be spinning before her eyes.) For this example, I used the Crop tool to crop the image to a perfect square, with my subject in the center. I ensured a perfect square by holding down Shift as I dragged the tool from one corner to the other. I then kept Shift held down as I repositioned the handles until the crosshairs at the center of the bounding box touched the subject's face. See 107 Crop a Portion of an Image for more on the Crop tool.
Create a Circular Cutout Copy Layer In the image, again with Shift held down, drag the pointer from one corner of the bounding box to the other, until the circle surrounds the subject matter perfectly. Choose Select, Inverse from the menu bar to invert the selection.
In the Toolbox, click the Elliptical Marquee tool. In the Options pane, set Feather to a fairly high amount, such as 40 pixels.
From the menu bar, select Layer, New, Layer from Copy. Name the new layer Cutout.
Apply Radial Blu
With the Cutout layer chosen, select Filter, Blur, Radial Blur from the menu bar. In the Radial Blur dialog box, specify the settings for the filter. Select the desired blur method, either Spin or Zoom. Specify the relative amount of blurring you want to apply to the image in the Amount field. As you change this setting, the diagram marked Blur Center changes to show the degree of alteration the blur will make to the image (there is no preview available). Here, the sweep of the arcs in the diagram represents the degree of change.
You can change the origin of the blur by dragging the wireframe pattern in the Blur Center pane. This origin is calculated relative to the center of the image, although the diagram appears to be square even when your image is not square.
The Quality setting determines whether Radial Blur takes its time to produce a less grainy, more believable effect. If you want to quickly apply the filter to see how it looks, click the Draft option. The Draft quality will be grainy, but it's quicker to produce. Best quality may take quite some time to render for images with very high resolution.
To finalize your choices, click OK. In a moment, the filter is applied to the chosen layer.
Using Best quality can cause banding in the image when you print. In addition, the time required to apply Best quality is substantially longer than for other settings.
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 changes or additions.
It isn't every family that has a grandmother who is willing to volunteer for witch duty. This particular Nana was showered with roses on her granddaughter's sixth birthdaywhich is a whole lot better reward than, say, having a house dumped on you.
To experiment with a more subtle application of the Radial Blur filter, try applying a blend mode to the Cutout layer. The Lighten mode gives the pattern a more ethereal quality, like the beginning of a dream sequence ("There's no place like home"). The Darken mode is still soft, but more ashen; darkening itself softly toward the edges for what could conceivably be a romantic effect.
Conceivably, this photo could have been reserved for the task about removing a green color cast. Instead, we placed Nana in the center of the legendary Oz effect. All that was rotated in this image is the circular cutout of the dining room details surrounding our witch; by feathering the selection from which the layer was cut, you can't really tell where the real world ends and the Radial Blur effect begins.