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One of the lesser-known capabilities in
Photoshop 6 is the Noise Gradient. An option when creating or
editing a gradient, it produces some truly wild gradients! While
they have their uses for complex masking (in some limited
circumstances), noise gradients are excellent for special
effects and creative accents.
Generally speaking, a noise gradient uses a
range of colors you determine, but rather than blending between
two colors, the Gradient Editor generates a series of colors and
blends them. The colors are randomly generated within the
parameters you set.
To begin the exploration of noise gradients,
open the Gradient Editor dialog box.
1. Select the Gradient tool in Photoshop's Toolbox.
2. Click once on the sample gradient in the Options Bar.
When the Gradient Editor opens, select Noise for
Gradient Type.
The Gradient Editor's options will change to
those shown here:
The first option to explore is Roughness.
Similar to the Smoothness slider for "Solid" gradients,
Roughness determines the abruptness of the transition between
colors. In the example below, there are five noise gradients.
The only difference among them is the Roughness setting. From
the top, they are 0%, 25%, 50%, 75%, and 100%.
At 300% zoom, you can see that each of the
stripes of color in the 100% Roughness sample is one pixel wide.
(It doesn't get any rougher than that, does it?) Keep in mind
that high levels of Roughness can produce pixelization when used
with non-linear gradients.
The default color model is RGB. Adjusting the
sliders determines what colors will be used to create the
gradient. Note the positions of the black and white sliders in
the following examples.
HSB (Hue/Saturation/Brightness) is an
alternative color model for noise gradient creation. In fact,
it's probably easier and more precise to use in most cases. This
is especially true if you want to create a gradient using only
tints of a particular hue. In this sample, note how smooth the
gradient is, even though Roughness is set to 50%. That is due,
in part, to the restricted range of brightness and saturation.
You can also use HSB color model to create a
grayscale noise gradient. Simply drag the white S slider all the
way to the left. Reducing the saturation of all colors to zero
produces gray.
The third color model available is L*a*b. This
mode allows you to produce in seconds very subtle gradients that
could take a tremendous amount of work in the Gradient Editor's
Solid gradient type.
Lab mode is also great for showing that you can
move the black and white sliders past each other. Compare the
"a" component sliders in the two samples below, and look at how
it affects the gradient.
So, we've seen RGB, HSB, L*a*b, and how to fake
a grayscale. What about CMYK? To the right of the sliders is a
checkbox labeled "Restrict Colors." When this option is
selected, the Gradient Editor will rein in the gradient, keeping
all colors within the CMYK gamut.
The checkbox immediately below, "Add
Transparency," does exactly that:
The Randomize button allows the Gradient Editor
to mix and match within the color range specified. You can click
it multiple times, experimenting until you see a gradient you
like. Remember, too, that you can adjust the sliders after
clicking the Randomize button to fine-tune the gradient.
Now that you've learned how to work with the
Gradient Editor to produce noise gradients, let's take a look at
my favorite use for them. Working with the Angle Gradient tool,
you can produce some very cool effects.
Circular noise gradients can also be useful.
You'll also find a grayscale noise gradient to
be perfect for creating those dusty beams of light streaming
through the window.... |