We pay so much to get the best and sharpest lenses, the highest resolution sensors, and top-rung software such as Photoshop and Lightroom, but then we spend even more money to blur all that sharpness. That's because too much detail often detracts the viewer from seeing the part of the image that we want seen. Sometimes too much sharpness just becomes motionless or static. Sometimes too much sharpness just doesn't convey that soft, silky "I'm in love" feeling. So, to make money, sometimes we have to destroy at least some of the sharpness that we spent so much time and money to get.
The most photographic of all the Photoshop blur effects is the one that imitates what happens when you intentionally keep the lens aperture as wide as possible to minimize depth of field. We used to use the Gaussian Blur filter for achieving that effect after the shoot, but it's a bit time consuming to use feathered selections and multiple applications to create a truly photographic look. So after listening to a lot of photographer's whine (Adobe's good at listening), Photoshop CS introduced the Lens Blur filter. Figure shows an image shot with a relative high shutter speed and small aperture. Although the model is definitely sharper than the rest of the image, the rest of the image is just too sharp to keep our attention focused on him. To make matters worse, the rest of the image was taken from another photograph and blurred slightly with the Gaussian Blur filterLens Blur filter to the rescue!
Figure. Applying Lens Blur to the background helps get our eyes back on the subject.
This is how the Lens Blur filter works best:
The Gaussian Blur filter is the old standby for blurring most anything. It's been around so long that surely anyone reading this book has been there and done that. Just be sure that when you use it on part of an image, you do it inside a feathered selection that will let the effect blend from sharp to blurry. Also remember that you'll want to match the noise in the image.
In Photoshop CS and later, there are quite a few variations on Gaussian Blur that will give you some special effects. The procedures and cautions for using them are the same as for other types of blurs. Here's a brief description of each of them.
There are so many motion blur filters that it's hard to keep track of them all. They all do the same basic thing: give the viewer the feeling are seeing an object captured while it was traveling at high speedso high that even a shutter fast enough to keep everything else in the image sharp couldn't keep the traveling object sharp.
I often find that it helps more to put a motion blur filter on an object that's been knocked out, even if that object originated in the same photograph and was just lifted from the photo. Otherwise the background smears as well as the subject. The result isn't quite as believable as when you blur a knocked-out subject, even if you've placed a selection around the image to be blurred. Figure shows an example of both techniques so you can see the difference.
Figure. On the left, the photo of the biker as it was shot. On the right the same photo after knocking out the biker and duplicating the knocked out layer to apply the blur.
Figure shows you the same object blurred with a third-party filter, Andromeda's Velociraptor, and a stroboscopic blur made in Photoshop, just to give you some idea of other ways to make a motion blur.
Figure. Blurred with Andromeda's Velociraptor.
There's also the Motion Trail filter in Alien Skin's Eye Candy 5: Impact (Figure). This is one of the most versatile motion blur filters because it will let you have the blur trail the object or start at its leading edge. You can also make the trail curve, taper, and change its opacity. All of this is done with sliders, so it's easy to see the effect before you apply it.
Figure. Both motion blurs were created with Eye Candy 5: Impact's motion blur filter. On the left, the blur starts trailing outside the selection or knockout. On the right, it starts on the leading edge of the selection.
There are two kinds of radial blurs in the Photoshop FilterRadial Blur menuZoom and Radial. The Zoom blur gives the viewer the feeling of moving in fast on the subject. It got its name from the fact that if you zoomed a video camera manually at very high speed and then looked at a frame captured midzoom, it would look a lot like the result in the Zoom mode of the Radial blur filter. The Radial blur filter gives you the feeling that the subject has been captured while spinning at a high speed while sitting in the center of a high-speed turntable. Examples of both are shown in Figures 10-12 and 10-13. Each of these figures is followed by a short description of how each effect was achieved.
Figure. The Zoom blur effect moves all our attention directly to the center of the image.
Figure. Radial blur.
The problem with making the Zoom blur work for you is that it wants to blur everything from the center out. More often than not, I want to see what I'm zooming in on. So I make a duplicate layer over the original, select the duplicate layer in the Layers palette, center the zoom, set the dialog settings that I like with the Preview box checked, and click OK. Then I take a big eraser brush, set it at 100 percent Opacity and make sure the brush is feathered to the max. Then, using a pressure sensitive pen, I erase through to the original image where I do not want the image to be blurred.
Usually, a feathered selection works well with the Radial blur when it comes to keeping intact the portion of the image you want to keep sharp. However, it didn't work very well for this thistle in Figure, thanks to its thorns. So, once again, I duplicated the image and then brushed through the radial blur duplicate with the eraser tool.