Compositing Images
Understand essential techniques for image compositing in Adobe Photoshop Elements, such as lighting, perspective, and the right composition.
Chapter Goals
The ability to composite images is perhaps one of the techniques that best illustrates the power of a photo editor. Image compositing is taking two or more images, or taking different areas in a single image, and bringing them together in another photo for either realistic final results or artistic expression. For example, poor uncle Ezekiel couldn’t make it last Christmas, but you want him in the family photo, so you take one photo of him and add it to your group photo.
There’s much to consider when compositing images or applying edits to different parts of a single image: lighting, perspective, and the right composition to make it appear realistic. It’s important to become familiar with certain rules to follow for compositing images so the final result looks realistic. You need to be certain subjects don’t float on backgrounds, the luminosity and brightness closely resemble all components, that the colors match, and hue/saturation levels are similar.
This chapter covers the many considerations you need to make when compositing images. You find out how to do the following:
Become familiar with essentials for compositing images
Understand perspective
Use Photomerge
Match color
Add shadows
Add photos to high grass
Knowing Compositing Essentials
There are some important essentials you should know when compositing images. As you examine photos, you should carefully look at the images you want to bring together. In some cases, it may be next to impossible to bring images together. In other cases, you might want to choose one image over another because your steps to composite with one image might be easier than with another image.
Here are some of the most important essentials for compositing images:
Perspective: Perhaps the single most important essential for image compositing is matching perspective between images. You need to become familiar with perspective rules and know something about horizon lines and vanishing points. When you have a mismatch in a composite image, the viewer immediately can see that the final image is a fake. People floating in air, proportion distortions, and unrealistic rotations are immediately viewed as fake by anyone seeing your final photos.
Figure 8.1 shows an exaggerated example, but it gives you the idea of issues in perspective. The image on the left shows the subject floating in air and obviously not properly placed in this composite. The problem is the horizon line for the background is where the water meets the sky. In the subject image on the right of Figure 8.1, the horizon line is at the top of the subject’s head, and the composite looks more realistic.
FIGURE 8.1 Horizon lines don’t match in the left image; the right image is a closer match of horizon lines.
Resolution: The resolutions of two or more images don’t have to be exact, but they should not be extremely different, such as 72 ppi for one image and 300 ppi for the other. When compositing images, choose Image > Resize > Image Size. Set identical resolutions for both images. If you need some scaling, you can scale images on the composite layers. Be careful to not upsize a photo. Increasing resolution can severely degrade your images.
Brightness and contrast: Adjust brightness and contrast after bringing one image into another. You can use a Levels Adjustment Layer and clip the Adjustment Layer to the layer where you adjust brightness and contrast. You should try to get a close match for brightness and contrast between images in the composite.
Film grain and noise: The thing to look out for when you try to composite two or more images is where there’s a lot of disparity in the noise level between the images. If you shoot one image at 100 ISO and another at 12,000 ISO, you’ll see quite a bit of disparity between the noise levels. In some cases, you might be able to use a background with high noise levels and blur the background to create a little more depth of field. But when using two or more foreground subjects and one has a high noise level whereas the other photo is absent of noise, the difference can be easily detected.
Scale: Scale images appropriately for the perspective. Unfortunately, the Elements Photo Editor does not provide an option to create a Smart Object. If you have the Elements+ plug-in, you can create Smart Objects. A Smart Object enables you to edit a layer nondestructively.
Nondestructive editing is particularly important when you scale a layer. While compositing, you find yourself moving, scaling, and observing results frequently. You try to finesse adjustments to try to get the best possible results that appear realistic.
If you scale a layer in the Photo Editor many times, the image will show obvious deterioration. One way to get around the problem is to use File > Place and place a photo on a layer in the Photo Editor. When using the Place command, the content comes in as a Smart Object. You can then scale and move the object many times without data loss. You need to convert the Smart Object to a simple layer using the Simplify Layer command in the Layer panel menu before you can apply other edits to the layer. However, use the File > Place command and address scaling as one of your first edits when compositing images in Photoshop Elements. For more on placing files in the Photo Editor, see the section later in this chapter “Placing Images.”
Placement: Scaling and matching perspective are very important when compositing images. Equally important is where you place an image in the composite. You have to continually be aware of the perspective and scaling as you move an image around the canvas.
Masking: When you create selections and add Layer Masks, the selections and ultimately the masks should be precise. If you have images with shadows, it’s often a good idea to include a part or all of a shadow in the mask. When you drop the image into a composite, you can edit the shadow to make a good fit.
Lighting: When you bring two or more images together in a composite, carefully observe the lighting and, in particular, the direction of the lighting. You want to avoid having two images with lighting coming from different directions. In Figure 8.2, you can see the obvious difference in lighting between the foreground subject and the background. The background photo was taken in harsh sunlight. The foreground subject was taken with much softer light.
FIGURE 8.2 Shadow on the subject is much less than the background elements.
Color balance: One of the last edits you make when compositing images is to balance color. Try to get the luminosity, saturation, and color balance matching in all images in the composite.
Blending: Be careful when using blending modes. The Darken group darkens all layers below the Darken layer. Likewise, the Lighten group lightens all layers below the Lighten layer. Areas that are darker make the background darker. When you want to use a blending mode to change values on one layer, be certain to create a clipping group. The same holds true for all Adjustment Layers.