Shake Reduction Previews
The Shake Reduction filter uses a multi-stage preview, regenerated each time you move the Blur Estimation Region, as well as whenever you change a setting. Photoshop CC initially displays a Coarse Preview, which usually shows up within a couple of seconds, providing a rough idea of where the focus is being improved. Don't judge the settings based solely on this preview, however; a grainy "pixel" effect is often visible at this stage (see Figure 5).
Figure 5 The Coarse Preview provides a rough look at the pixels being changed while Adobe Photoshop CC generates the Fine Preview.
As you examine the coarse preview, Photoshop generates a Fine Preview. This process takes roughly 10–15 seconds in most cases, and when finished it often smoothes out any "crunchy" pixels, giving you a more accurate means of judging the quality of the correction (see Figure 6).
Figure 6 The Fine Preview provides a means of more accurately judging the quality of the sharpened details.
Also note the loupe-like Detail preview in the lower-right portion of the window (see Figure 7). You can detach and float this window around to preview small areas of the image at 50, 100, 200, or 400% magnification. This preview lets you examine specific groups of pixels without having to pan the main preview around and switch its magnification frequently.
To target specific details with the Detail preview, move the cursor over the main preview until you see a crosshair. Click the pixels you'd like to preview, and they'll appear in the Detail area. You can also pan the Detail preview by clicking and dragging.
Figure 7 The Detail preview works like a loupe, allowing you to zoom in at predefined magnification levels.
You can switch the default location of the Blur Estimation Region to use the location shown in the Details preview. Click the gray button in the lower-left corner of the Detail preview, and the region location will change while the main preview regenerates.