Step 1:

The Iris Blur is sort of the opposite of Field Blur. It blurs everywhere but where you have a pin. Each single pin blur is its own little self-contained editable container. You get a decent amount of control and it can lead to some very cool effects. Go Filter>Blur>Iris Blur to add an Iris Blur to your image.

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Step 2:

Its simple, one pin in the center of your document. There are a whole bunch of neat things you have at your disposal to work with this blur. First and foremost you still control the amount of blur by clicking and dragging your mouse around between the inner and outer rings.

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Step 3:

You can control the area the blur fades into by clicking and dragging the small squares at the four points on the surrounding oval. The top and bottom points control top-to-bottom size and the left and right points control left-to-right size. Using these points you can also rotate your oval.

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Step 4:

Select the center of the pin to drag the blur around. The large box on the outer oval controls the rounded-ness of the corners and you can convert this to a rounded rectangle by simply dragging this handle.

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Step 5:

You can also control the fall-off of the blur by dragging the four inner dots in or out. TIP: Hold your Alt/Opt key to drag only one dot at a time for even more control.

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Step 6:

You can add a second area of the image that you would like to be sharp by simply clicking to drop a second pin. Make the adjustments you want and hit OK to commit the Iris blur.

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