Photoshop cs5 cho nhiếp ảnh gia part 60 pps

Blending Modes Before proceeding with ways to combine images, you need to have some understand-ing of blendunderstand-ing modes.. figure 9.27 shows the results when a Background layer of

Tr y It! Open the image called FilterGallery from this book’s companion website, www.sybex com/go/photoshopnature, or open one of your own images, and experiment with a variety of filters Try different combinations and orders of filters while varying the settings

Digital Montages

Combining shots, or creating “slide sandwiches,” has been a popular film technique for years traditionally, one slide had to be overexposed by about two stops and the other by a single stop to yield an acceptable exposure at best, it’s an approach that requires a lot of trial and error and bracketing

it’s not only possible to emulate these same effects in Photoshop; it’s actually easier to do so! One reason is that we have the flexibility to alter exposures as needed

another reason is that if you didn’t think of using a particular image as part of a mon-tage while you were in the field, it doesn’t matter You can make several versions of the same file in Photoshop and in Photoshop, you can go further and combine numerous images in a variety of ways

Before you begin to make your montages, remove any dust in your images

after all, double the dust means double the cleanup required later! final exposure and color changes are usually best made after creating the montage

Blending Modes

Before proceeding with ways to combine images, you need to have some understand-ing of blendunderstand-ing modes

Back in Chapter 5, you learned about layers recall that in many ways, pixel layers in normal blending mode—which is what we’ve been using—act like prints

Whatever is on top is what you see if you “cut a hole” in the top layer by using a layer mask to partially hide that layer, you see what’s underneath if you reduce the opacity

of the top pixel layer, you see some of the top layer and some of the layer beneath it in normal mode, the layers blend together in an intuitive way

However, Photoshop at its core is a series of mathematical algorithms, and there

are other instructions (algorithms) for how to blend two layers these are called blend­

ing modes Photoshop Cs5 and elements 8 have 27 blending modes Don’t panic! You

don’t have to memorize what each one does instead, you can simply scroll through the drop-down list in the Layers panel (see figure 9.26) You’ll soon realize that the most useful blending modes for photographers are normal, Multiply, screen, Overlay, soft Light, Difference, and Luminosity But sometimes one of the other modes will create magic for you, so don’t hesitate to try them all

each blending mode is a different set of instructions for how to combine two layers if you are more intuitive, don’t worry about fully grasping each algorithm feel free to skip ahead and experiment with using the blending modes in case you are more analytical, we’re providing this explanation

the different blending modes are grouped together in the drop-down list accord-ing to similar functions

Figure 9.26 Photoshop offers

numerous blending modes to combine layers in different ways

figure 9.27 shows the results when a Background layer of an image is copied and flipped horizontally upon itself in six different blending modes note that for this image,

exclusion and Hue provided interesting results, so they were included in this illustration

Hue Exclusion

Difference Overlay

Figure 9.27 Compare the results obtained by copying the background, flipping the image, and then varying the blending mode.

Note: On a Windows system, to preview the effects of the various blending modes, scroll through them by highlighting the top pixel layer and clicking Shift++ (plus) or Shift+– (minus)

Surreal Montages

a popular effect that photographers seek is a dreamy blur You’ve seen it in many

artistic photos: a kind of glow or soft focus around the subject that we call a surreal montage (see an example in figure 9.28) even the most mundane subjects can become

evocative when done in this way

Figure 9.28 Surreal montages

seem to have an ethereal glow around them that makes them quite evocative

Note: The surreal montage in Figure 9.28 would not be possible using film because of the amount

of white and nearly white in the image This is a distinct advantage of digital photography

the traditional way to capture a surreal dream montage is to take two shots with your camera on a tripod, not moving it between shots take one image two stops overexposed at f22 or comparable and sharply focused, and the other one stop overex-posed with a wide-open aperture and blurred Defocus in the direction that makes the blur get larger than the subject rather than smaller, because the blurred version is going

to provide the glow around your subject the first image is going to provide the detail

With a film camera, you couldn’t use a wide-angle lens because the blur would

be insufficient You were also limited to subjects that were close to middle-toned if you wanted to do a surreal montage of a light subject, it was often impossible because you would lose all detail in the overexposed versions

Photoshop enables you to go beyond these restrictions and create surreal mon-tages using any lens, since you can use a Gaussian blur to blur the image as much as needed also, you can capture light images while retaining detail and adjust the expo-sure after the fact as necessary

Note: For slightly different effects, experiment with some of the other Blur tools

if you know you want to make a surreal montage, go ahead and capture two versions of the image as described in the preceding paragraphs However, if it wasn’t

until editing your pictures that you realized an image would be great as a surreal

mon-tage, convert the same image twice, making one considerably lighter than the other

You can try plus-two and plus-one exposures in the raw converter, but we often try to

avoid clipping any data, so adjust the exposures accordingly since some of the glow

results from areas without detail, you may choose to allow some clipping this is a

matter of experimenting and seeing what effects you prefer You can always lighten

the exposure of the composite using Levels or Curves

to create the surreal montage, take the following steps:

1. Open your two images, as shown in figure 9.29

Figure 9.29 Open a light

but detailed image as well as

a slightly darker but blurred version of the same image

2. select the Move tool , and while holding down the shift key, drag the

darker, blurred image on top of the lighter one

3. Change the blending mode of this layer (in the Layers panel) to Multiply

4. if the blurred layer is not as blurred as you would like, select that layer and

make it a smart Object by choosing Layer > smart Object

5. Choose filter > Blur > Gaussian Blur if you are working from an in-focus

origi-nal, you may need a blur ranging from 15 to 40, depending on the amount of

detail in the original image the advantage of working this way is you can judge the necessary amount of blur in real time

6. adjust the overall exposure as needed with a Curves or Levels adjustment layer

For Photoshop Elements Users: Surreal Montages

Since Smart Filters are not available in Elements, follow the same steps as for Photoshop, but apply the Gaussian blur directly on the image layer, if needed

You can create a similar but slightly different effect by combining two images that are underexposed by one to two stops instead of using the Multiply blending mode, choose screen figure 9.30 shows the original image and a version created using Multiply and another by using screen Which approach is better will vary by image and whether the detail you want to retain is primarily in the lighter or darker tonalities

Multiply Screen

Figure 9.30 Creating surreal montages using the Screen or Multiply blending modes yields slightly different results In this case,

we prefer the Screen results, but in other cases Multiply will do a better job

For Photoshop Elements Users: Surreal Montages

Since Smart Filters are not available in Elements, follow the same steps as for Photoshop, but apply the Gaussian blur directly on the image layer, if needed

Note: You may want to experiment with using the Overlay or Soft Light blending modes instead

of Multiply The effect is a little different, and depending on your individual taste as well as on the particular image, you may prefer one over the other With these blending modes you may not need the images to be quite as light as with Multiply You’ll notice an increase in contrast and saturation

Mirror or Flip Montages

another approach to combining images is to take the same image and combine it with

a second identical shot that is rotated 90° or flipped 180°; andré Gallant calls these

mirror montages this can yield some amazing abstract designs

One of the keys is to experiment with the different blending modes Often, Multiply, Overlay, Difference, exclusion, Luminosity, or Color yields some

interest-ing results Usually you begin with well-exposed images and lighten the montage as

needed after you combine the layers Depending on the choice of blending mode, you

may or may not need to adjust the exposure

to create mirror or flip montages, take these steps:

1. Open an image, and duplicate the Background layer by dragging it to the

Cre-ate a new Layer icon

2. Ctrl+click/F+ the icon for the Background copy layer to select it

3. Choose edit > transform > rotate, and select 90° in either direction or flip

horizontal or vertical the choice depends on the particular image and what you think might look good

4. scroll through the different blending modes to see what looks good sometimes

nothing works, and sometimes you hit a winner, as you can see in figure 9.31

Figure 9.31 Flipping this image horizontally and selecting the Difference blending mode resulted in a dramatic abstract

design

5. if you have elected to rotate your image 90°, chances are you will want to crop and use the center square formed by the overlap of the two images

6. sometimes you can repeat the process and copy the montage, rotate, or flip it and blend it to create a virtual kaleidoscope (figure 9.32)

Figure 9.32 All sorts of abstract designs—even kaleidoscopes—are possible by combining mirroring techniques,

rotations, and blending modes

Tr y It! Open the image called Flip on this book’s companion website, www.sybex com/go/photoshopnature, or open one of your own Duplicate it, and then rotate or flip it

to create various effects Be sure to scroll through the blending modes to see how they affect the montage

Mirror Images

Mirror images are very similar to flip montages, except that the two images are side

by side rather than on top of each other this creates an obvious dramatic symmetry that can be quite compelling natural phenomena that have strong design compo-nents, such as sand dunes, rock formations, waves, and even trees, lend themselves to this approach remember that the center of your image is formed by what is on the edges of your file, so your subject may need to be placed toward the edges of the origi-nal rather than your typical composition

to create a mirror montage, take the following steps:

1. Open your file (see figure 9.33), and duplicate it by choosing image > Dupli-cate this is easier for this technique than simply copying the Background layer,

as you did earlier