Absolute Beginner's Guide to Digital Photography

3. Click Filter, Despeckle again or press Ctrl+F (xF for Macs) to run the filter
   again.

The film or paper grain pattern will slowly fade into the image. You also will see the

moiré disappear. In some cases, you might have to repeat the process. The following

images show the scanned photo before and after the Despeckle filter was applied

four times (see Figure 13.12).

CHAPTER 13 THE IMPORTANCE OF FILTERS 201

FIGURE 13.12
Image before
and after using
Despeckle.

Using Dust & Scratches

The Dust & Scratches filter provides several slider bars for removing dust and

scratches from image scans. This filter works best on areas with little detail, such as

skies and solid-colored walls that have excessive dust. This filter includes two slider

bars:

■ Radius. The radius in pixels that Photoshop searches for differences among

pixels. Always adjust this number first.

Larger numbers blur the image, so use the smallest number possible. This

blurring effect is one reason why Dust & Scratches should only be used on

large areas with little detail, such as the sky.

■ Threshold.This slider sets the degree of difference among pixels that will be

affected by the filter.

Adjust this slider after finding the appropriate radius value. Start at zero and

then move the slider to the right until detail emerges, but dust does not. The

higher the better, but not too much or the dust will reappear.

The best way to remove dust is not to scan it. Use an antistatic brush and a pair of

antistatic gloves, and never touch the negatives with your hands. You can find anti-

static brushes at your local camera store.