Iris Blur

The Iris Blur filter offers comprehensive onscreen controls for designating both the location and intensity of the blur effect. Upon first glance, the controls may appear rather simplistic. After just a bit of exploration, however, you come to realize they are quite powerful and flexible. I’ve labeled the filter's various controls in the example below.

The outer boundaries of the ellipse define the start of the transition between the area to be blurred and the area to be protected. The feather handles define the actual portion of the image that is to protected, remaining in sharp focus. The ellipse and feather handles can be adjusted independently.

As with the Field Blur filter, you control the intensity of blur by dragging on the adjustment ring or by moving the Blur slider located in the right panel. Once activated, the Iris Blur filter automatically sets a pin in the center of the image.

The primary control point is the ellipse surrounding the pin. The area outside the boundaries of the ellipse will be blurred at full strength. There are four Ellipse Handles (small squares) along the ellipse as well as a larger Roundness Knob. Click on a handle and drag to alter the height or width of the ellipse. Click and drag on the Roundness Knob to change the corner shape of the ellipse from an oval (shown above) to a rounded rectangle (shown below). 

Here I dragged the Roundness Knob to change the shape of the ellipse to a rounded rectangle. Hovering the cursor alongside an Ellipse Handle and dragging will rotate and/or resize the ellipse. Clicking and dragging inside the ellipse repositions the entire control unit.

The Feather Handles encompass the area to remain completely protected from the blur adjustment. They also define the scope of the transition gradient between the protected area and that with a partially applied blur. The further away these handles sit from the edge of the ellipse, the more gradual (and seamless) the blur transition. Click and drag on any single Feather Handle to move all of them as a unit. You can adjust a single Feather Handle by holding the Option/Alt key as you click and drag.

Confused? Don't be. This behavior is much harder to explain to to actually use. The easiest way to start is to simply move these handles right to the edge of the portion of the image that should remain in focus. Make even minor adjustments to the Feather Handles and you will see the transition from partially blurred to non-blurred areas update.

Here's the original file. Even though it was shot wide open, the background remains distracting. Using Iris Blur I was able to soften the background while keeping the subject in focus.

Tilt-Shift 

The Tilt-Shift filter emulates the optical effects of extreme perspective control lenses, like those made by LensBaby. When you first open the filter an adjustment ring is placed at the center of the image with a set of horizontal lines appearing on either side of it (see below).

The filter opens with a pin in the center of the image. Here I have moved the entire control unit down and adjusted repositioned the dashed lines. The bottom dashed line now sits below the image area, as indicated by the truncated set of dashes (circled in red).

The dashed lines establish the boundary between completely blurred portions of the image and the start of a transition to the protected image area which sits inside the solid lines. The simplest way to think of this is that the portion of the image to be protected from the blur must reside within the solid lines.

You can move the entire control unit by clicking and dragging on the pin. You can also move the dashed and solid lines independently by clicking and dragging on any of them. Although the filter opens with a horizontal tilt adjustment, you can rotate the entire control unit by clicking and dragging just outside the small circle located in the middle of either solid line. As is common in Photoshop, you can constrain your rotation by holding the Shift key as you drag. A 'rich cursor' display (new to CS6) will appear indicating the current angle of rotation. As with the previous filters, you control the intensity of the blur by dragging either the adjustment ring or by moving the Blur slider in the right panel.

The panel on the right side of the interface includes a Distortion slider, which by default is set to 0%. Moving the slider in either direction will add a motion blur effect to the area that by default would be the foreground in a horizontal image. Note that if the control unit is rotated 90 degrees clockwise then this 'foreground' area will then sit on right. The Symmetric Distortion check-box causes this distortion to be applied to both sides of the blur effect.

Moving the Distortion Slider adds a motion effect to the blur and bokeh, as you can see in the top portion of the image. The direction of the motion is linked to the direction that you move the slider.

We've now looked at the main features of each filter. But there is a second Bokeh Effects panel sitting underneath the blur filters. We'll take a look at its options on the following page.

Click here to continue reading our Photoshop CS6 Blur Gallery tutorial...