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ptg 294 Chapter 17 Applying the Motion Blur filter One way photographers capture the blur of motion (e.g., in sports or wildlife photography) is by panning the camera as the subject is moving. In Photoshop, you can create a similar illusion of motion by using the Motion Blur lter. In the fol- lowing instructions, you’ll blur the whole image by applying the lter as a Smart Filter, then to bring a key area back into focus, remove the eect from part of the image by painting on the lter mask. To apply the Motion Blur filter to part of an image: 1. Click an image layer and duplicate it by pressing Ctrl-J/Cmd-J. A 2. Right-click the duplicate layer and choose Convert to Smart Object. 3. Choose Filter > Blur > Motion Blur. e Motion Blur dialog opens. B 4. Lower the zoom level for the preview. Choose a Distance value for the amount of blurring, choose an Angle value for the direction of the blur, then click OK. C 5. On the Layers panel, click the lter mask thumbnail for the Smart Filters listing. 6. Choose the Brush tool (B or Shift-B). On the Options bar, choose a medium-sized Soft Round brush and an Opacity of 80%. Choose black as the Foreground color. 7. Paint over the area of the image that you want to hide the Motion Blur eect from and restore focus to ( A–B , next page). Since your brush isn’t at full opacity, you can repeat your strokes in any area to hide even more of the motion blur. 8. If you have masked too much of the Motion Blur eect, press X to make the Foreground color white, then apply strokes to restore it. ➤ To readjust the Motion Blur lter settings, double-click the lter listing on the Layers panel. A i s i s t h e o r i g i n a l p h o t o . B In the Motion Blur dialog, we chose a Distance value of 64 px and set the Angle dial to match the angle of the motorcycle. C e M o t i o n B l u r l t e r w a s a p p l i e d t o t h e w h o l e i m a g e . ptg Refocusing 295 B e n a l r e s u l t s c o n v e y f a s t m o t i o n . W e w e r e c a r e f u l not to remove the Motion Blur eect from the tires, since they would be moving too fast to stay in focus. A We clicked the lter mask thumbnail on the Layers panel, then applied strokes with black to hide the Motion Blur eect. Using the Sharpen tool When used with the new Protect Detail option checked on the Options bar, the Sharpen tool enhances details without introducing noticeable artifacts. With this tool, you can sharpen areas selectively without having to use a mask. Note: To sharpen an entire image, see the remaining pages in this chapter. To use the Sharpen tool: ★ 1. Click an image layer, then duplicate it by pressing Ctrl-J/Cmd-J. C 2. Choose the Sharpen tool. 3. On the Options bar, choose a Strength value, and check Sample All Layers and Protect Detail. 4. Press [ or ] to adjust the brush diameter, then drag across any area that needs sharpening. D For stronger sharpening, drag again in the same area. C i s p h o t o h a s a s o f t f o c u s . D With the Sharpen tool, we easily sharpened just the eyes. ptg 296 Chapter 17 To apply the Smart Sharpen filter: 1. Open a photo that needs sharpening. A On the Layers panel, click an image layer or the Back- ground, then press Ctrl-J/Cmd-J to duplicate it. Right-click the duplicate layer and choose Convert to Smart Object. 2. Choose Filter > Sharpen > Smart Sharpen. e Smart Sharpen dialog opens. Move it out of the way so the document is still in view. ➤ Keep the zoom level for the preview at 67% or 100%. To bring a dierent area of the image into view, either drag in the preview or click in the document. 3. Check More Accurate to produce high-quality sharpening by allowing multiple passes of the l t e r . i s t a k e s l o n g e r b u t i s w o r t h t h e w a i t . 4. From the Remove menu, choose an algorithm for the correction: Gaussian Blur is a good, all- purpose choice; Lens Blur sharpens details with fewer resulting halos (we like this option); and Motion Blur is useful for correcting blurring due to movement of the camera or subject, but for this option you need to know that angle of movement. Applying the Smart Sharpen filter Most digital photos need to be sharpened, and the need becomes greater if you change the le’s dimensions or resolution with the Resample Image option checked, convert it to CMYK Color mode, or apply a transformation command to it. To sharpen an image, you can use either the Smart Sharpen lter or the Unsharp Mask lter (the latter, despite its name, has a sharpening eect). ese lters can add noise to an image and therefore should be applied after image-editing, adjustment, and color correction. High-resolution printing also causes some minor blurring due to dot gain. You can anticipate and compensate for this by sharpening the image once again as you prepare it for output. Experience will teach you how much sharpening is needed. e Smart Sharpen lter, discussed rst, gives you the ability to sharpen (and fade the sharpen- ing) in the shadow and highlight areas separately, whereas Unsharp Mask (see pages 299–300) doesn’t provide that control. We usually use the Smart Sharpen lter for targeted sharpening and the Unsharp Mask lter for output sharpening. (See also the sidebar below.) A Because the Smart Sharpen lter will let us control which tonal areas in the image are sharpened, it will be the right choice for correcting this blurry portrait (the resolution of this image is 300 ppi). ADVANTAGES TO USING THE SMART SHARPEN FILTER We use both the Smart Sharpen and Unsharp Mask fi lters on a regular basis. Smart Sharpen offers the following advantages, though, in addition to the one mentioned in the paragraph above: ➤ With the More Accurate option checked, Smart Sharpen applies sharp- ening in multiple passes. ➤ Smart Sharpen has the ability to detect edges, so it produces fewer color halos than Unsharp Mask. ➤ Smart Sharpen lets you choose from three algorithms (to correct Gaussian blur, lens blur, or motion blur), whereas Unsharp Mask corrects only Gaussian blur. ➤ Smart Sharpen lets you save and reuse your settings, for greater speed and consistency in your workfl ow. ptg Refocusing 297 5. Try an Amount value of 60–150% for the degree to which contrast will be increased, and a Radius value between 1 and 2.5 pixels. You can use the scrubby slider for all the sliders in this dialog. e image should now look slightly oversharpened. A You’ll fade the eect next. 6. To control the amount of sharpening in the shadow and highlight areas, click Advanced, then click the Shadow tab. B Drag in the pre- view to display an area of the image that con- tains both shadows and midtones, then make the following adjustments: Choose a Radius value (between 5 and 10) to control how many neighboring pixels will be compared to a specic pixel. e higher the Radius, the larger the area to be compared. Change the Tonal Width value to control the range of midtones to be aected by the Fade Amount. e higher this width, the wider the range of midtones aected and the more gradu- ally the sharpening will fade into the shadows. Move the Fade Amount slider until you see the desired reduction of oversharpening in the Continued on the following page A e s e t t i n g s w e c h o s e i n t h e B a s i c p a n e l o f t h e S m a r t S h a r p e n d i a l o g ( s h o w n a b o v e ) s u c c e s s f u l l y s h a r p e n e d k e y d e t a i l s i n the photo, such as the eyes and lips, but in the process, also oversharpened the skin (now the pores look too pronounced). B In the Shadow tab (Advanced panel), we chose a moderate Fade Amount to soften the sharpening in the shadows (such as around the eyes) and a moderate Tonal Width value to fully sharpen the shadows but only partially sharpen the midtones. ptg 298 Chapter 17 A Finally, in the Highlight tab of the Smart Sharpen dialog, we chose a moderate Fade Amount to soften the sharpening in the broad, at highlight areas of skin and a moderate Tonal Width value to fully sharpen the highlights and partially sharpen the light midtones. B Compare this original image to the nal image at right. C e S m a r t S h a r p e n l t e r a d d e d c l a r i t y t o t h e f a c i a l f e a t u r e s w i t h o u t applying unattering sharpening to the cheeks and forehead. shadows. If the Tonal Width value is too low, the eectiveness of this slider will be limited. 7. Click the Highlight tab. A Drag the image in the preview to display an area that contains both highlights and midtones. Adjust the Radius, Tonal Width, and Fade Amount values, as in the preceding step. 8. Hopefully, just the key details or features of the image are sharper. If the overall image now looks too sharp, click the Sharpen tab and reduce the Amount value slightly. 9. Click OK. B–C ➤ To save the current settings as a preset, click the Save a Copy button in the dialog, enter a name, then click OK. Saved settings can be chosen from the Settings menu for any image. ➤ To compare the unsharpened and sharpened versions of the image, press on the dialog preview, then release. ➤ To modify the Smart Sharpen results, double- click the Smart Sharpen listing on the Smart Object layer; the dialog reopens. ptg Refocusing 299 Applying the Unsharp Mask filter To do its job of sharpening an image, the Unsharp Mask lter increases the contrast between adjacent pixels. You will need to choose three variables in the dialog: Amount, Radius, and reshold. To apply the Unsharp Mask filter: 1. Choose a zoom level of 50–100% for your image, then duplicate an image layer (Ctrl-J/Cmd-J). A 2. Right-click the duplicate layer and choose Convert to Smart Object. 3. With the Smart Object layer selected, choose Filter > Sharpen > Unsharp Mask. e Unsharp Mask dialog opens. Move it out of the way, if nec- essary, so the document is still in view. 4. Choose an Amount percentage to control how much the contrast is increased. Use a low setting (try 80–100) for gures or natural objects or a higher setting (150–170) for sharp-edged objects. For a high-resolution image (2000 x 3000 pixels or higher), try an Amount of 130–170. B ➤ Uncheck, then recheck Preview to compare the original and sharpened images. Choose a zoom level for the preview of 50–100%. To bring a dierent area of the image into view, either drag in the preview or click in the document. 5. e Radius aects how many neighboring pixels around high-contrast edges the lter aects. When choosing an appropriate Radius, you need to consider the pixel count of the image and its subject matter. C e higher the pixel count, the higher the Radius value needed to achieve the desired result. For a low-contrast image that contains large, simple objects and smooth transi- tions, try a high Radius of 2 (you’ll rarely need to use a higher value), whereas for an intricate, high-contrast image containing many sharp tran- sitions, try a lower Radius of around 1. Note: e Amount and Radius settings are inter- dependent, meaning if you raise the Radius, you’ll need to lower the Amount, and vice versa. 6. Choose a r e s h o l d value (0–255) to establish how dierent in value an area of pixels must be from a high-contrast edge to be aected by the l t e r ( A , next page). Start with a reshold value of 0 (to sharpen the entire image), then increase Continued on the following page C …and a high Radius value of 3.3 produced halos around the watch hands and numerals. A e o r i g i n a l 3 0 0 p p i i m a g e i s s l i g h t l y b l u r r y . B A high Amount percentage for the Unsharp Mask l- ter produced halos along the edges of the watches… ptg 300 Chapter 17 it slowly. At a reshold of 5–10, high-contrast areas will be sharpened and areas of lesser contrast will be sharpened much less. When increasing the reshold, you can also increase the Amount and Radius to sharpen the edges. ankfully, the lter won’t oversharpen the low- contrast areas. 7. Click OK. B To adjust the settings at any time, double-click the Unsharp Mask listing on the Layers panel. ➤ If the sharpening produced color halos along the edges of the objects, choose Luminosity as the blending mode for the Smart Object layer. is will limit the sharpening to luminosity values and remove it from hue and saturation values. B e v a l u e s s h o w n a b o v e ( n o t e e s p e c i a l l y t h e l o w e r r e s h o l d v a l u e ) p r o d u c e d t h i s n a l , a n d properly sharpened, version of the image. A With a high reshold value of 12 chosen in the Unsharp Mask dialog, the lter sharpened only high-contrast edges but left the watchbands and background still blurry. SUGGESTED SETTINGS FOR UNSHARP MASK For an image that is 2000 x 3000 pixels or larger, try using these values: Soft-edged subjects, such as landscapes Amount 100–150, Radius 1–1.5, Threshold 6–10 Portraits Amount 100–120, Radius 1–2, Threshold 4–6, or to the point where skin areas start to look smoother Buildings, objects, etc. for which contrast is a priority Amount 150–200 or more, Radius 1.5–3, Threshold 0–3 . bring a key area back into focus, remove the eect from part of the image by painting on the lter mask. To apply the Motion Blur filter to part of an image: 1. Click an image layer and duplicate. (e.g., in sports or wildlife photography) is by panning the camera as the subject is moving. In Photoshop, you can create a similar illusion of motion by using the Motion Blur lter. In the fol- lowing. and consistency in your workfl ow. ptg Refocusing 297 5. Try an Amount value of 60– 150% for the degree to which contrast will be increased, and a Radius value between 1 and 2.5 pixels.
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