Graphics Programs Reference
In-Depth Information
Depth Map . This is where you tell Elements what to use as the source point for the blur.
You can choose None (everything's blurred), Transparency, or Layer Mask. The Blur
Focal Distance slider is probably the most important setting in this window, because it
tells the filter where to center the in-focus part of the photo. Remember, your layer mask
is in shades of black and white. You can use the Blur Focal Distance slider to tell Ele-
ments which part of the masked area should be in focus. Black is 0 and white is 255, so if
you chose 100, for example, you'd be selecting an area covered by the medium-gray part
of the mask. It's often easier just to click in the preview area to tell Elements where you
want the most focused part to be; when you do that, the focus shifts to the spot you
clicked. The Invert checkbox swaps the effect so that what was in focus becomes blurred,
and what was blurred becomes focused.
Iris . This section may seem a bit confusing at first if you've never paid much attention to
how a camera's lens operates. And, really, the most important setting here is the Radius
slider, which sets the maximum amount of blur in the image. So unless you know what
you're doing, just focus on the Radius slider and ignore the other settings in this section
(leave them at their original settings). But, if you're interested, here's what they do:
Think of a camera lens as working something like an eye. The iris area of an eye controls
the size and (in some animals) the shape of the pupil. In the same way, the aperture of
your camera is controlled by a mechanism also called an iris ( iris diaphragm , actually).
The overlapping blades that open and close so that light can reach the camera's sensor
may be in many different patterns. This setting gives you some choice in just what kind
of iris you want Elements to simulate. The Shape menu lets you choose what shape the
iris should be. The Radius slider sets the maximum amount of blur in the image, Blade
Curvature determines how round the iris is, and Rotation controls how much the iris is
rotated, since an iris is rarely a perfect circle, because of the blade configuration. Think
of the iris in a cat's eye in bright light where the pupil is more like a slit than a
circle—Rotation would tell Elements how much to rotate that slit from perpendicular.
Specular Highlights . These settings sound awfully complicated, but they're actually
pretty simple. If you look at photos with a good bokeh, there tends to be a certain amount
of light bloom —a kind of overbrightness in the very bright highlights. (If you look back
at Figure 13-9 , you can see examples on the deck and in a couple of the leaves.) To mim-
ic that, use the Brightness slider to determine how bright your out-of-focus highlights
are, and the Threshold slider to determine how bright pixels must be in order for them to
be affected by the Brightness slider.
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