Adobe Premiere Pro CS4 - Manual (Page 349)

343 USING ADOBE PREMIERE PRO CS4
Effects and transitions
Last updated 11/6/2011
Shadow Radius and Highlight Radius The radius (in pixels) of the area around a pixel that the effect uses to determine
whether the pixel resides in a shadow or a highlight. Generally, this value should roughly equal the size of the subject
of interest in your image.
Color Correction The amount of color correction that the effect applies to the adjusted shadows and highlights. For
example, if you increase the Shadow Amount value, you bring out colors that were dark in the original image; you may
want these colors to be more vivid. The higher the Color Correction value, the more saturated these colors become.
The more significant the correction that you make to the shadows and highlights, the greater the range of color
correction available.
Note: If you want to change the color over the whole image, use the Hue/Saturation effect after applying the
Shadow/Highlight effect.
Midtone Contrast The amount of contrast that the effect applies to the midtones. Higher values increase the contrast
in the midtones alone, while concurrently darkening the shadows and lightening the highlights. A negative value
reduces contrast.
Black Clip, White Clip How much of the shadows and highlights are clipped to the new extreme shadow and highlight
colors in the image. Be careful of setting the clipping values too large, as doing so reduces detail in the shadows or
highlights. A value between 0.0% and 1% is recommended. By default, shadow and highlight pixels are clipped by
0.1%—that is, the first 0.1% of either extreme is ignored when the darkest and lightest pixels in the image are identified.
These are then mapped to output black and output white, ensuring that input black and input white values are based
on representative rather than extreme pixel values.
Blur and Sharpen effects
Antialias effect (Windows only)
The Antialias effect blends the edges between areas of highly contrasting colors. When blended, colors create
intermediate shades that make transitions between dark and light areas appear more gradual.
Camera Blur effect (Windows only)
The Camera Blur effect simulates an image leaving the focal range of the camera, blurring the clip. For example, by
setting keyframes for the blur, you can simulate a subject coming into or going out of focus, or the accidental bumping
of the camera. Drag the slider to specify a blur amount for the selected keyframe; higher values increase the blur.
Channel Blur effect
The Channel Blur effect blurs a clip’s red, green, blue, or alpha channels individually. You can specify that the blur is
horizontal, vertical, or both.
Select Repeat Edge Pixels to make the blur algorithm operate as if the pixel values beyond the edge of the clip are the
same as those of the edge pixels. This option keeps edges sharp, preventing the edges from darkening and becoming
more transparent—the result of being averaged with a lot of zeroes. Deselect this option to make the blur algorithm
operate as if the pixel values beyond the edge of the clip are zero.