Intro to Compositing
Intro | Multi-RAW Processing | Creating HDR Images by Hand [Part I] | Creating HDR Images by Hand [Part II] | Sharpening in LAB Color | Converting to Black and White | Using LAB Color Adjustments | Inverting Backgrounds with LAB | Intro to Compositing | HDR in Adobe Photoshop CS5 | Using Image Apply Image | Aging Photos Roundup | Making Colors Pop in Photoshop
Intro Image: To create this photo composite, I shot a macro of a marble and its shadow, and then used Photoshop to add the view of the ocean in place of the natural shadow.
Compositing, or photo compositing, is the technique—art and craft—of combining images to create a new image. The newly created image often presents its own version of reality.
Compositing is often used in advertising, where the use of the technique is sometimes intended to be obvious and at other times is designed to be seamless. Compositing has sometimes been used in journalism, although this use is generally frowned upon when discovered. The opprobrium hasn’t stopped the usage—for example, the Communist party under Stalin used old-fashioned compositing to “purge” out early party leaders as they were discredited by altering historic photographs to remove those who had been purged from the party.
Compositing comes into its own as a fine art technique, where concerns are conceptual, aesthetic and visual rather than related to factual concerns, ethics and marketing. This article concentrates on compositing to create art images—in any case the techniques are essentially the same no matter what the intended usage.
As art, photo composites usually present essentially unreal or “impossible” worlds (this phrase has been used as a description of M.C. Escher’s work, and I like to apply it to many of my photo composites).
Thus, the heritage for compositing extends back to so-called surrealist artists such as Salvador Dali, Rene Magritte and the great M.C. Escher. Creating a plausible impossibility is an important part of the task faced by any would-be photo compositor. Therefore, it’s important to study how these artists managed it, working in non-photographic mediums.
Turning to photography, there’s a rich tradition of compositing in the chemical darkroom that notably includes Man Ray and Jerry Uelsmann. This is a side of photography that has co-existed along side traditional “straight” photography on a parallel track—and perhaps has never quite been given the respect and acknowledgment that it deserves. With compositing, photography explicitly leaves the kingdom of capturing “what is really there”—and becomes a new art form that uses photographs as input, grist for the mill of imaginative image creation.
With the advent of digital and creative post-processing in Photoshop, the name of the game has changed as you’ll see in this article.
Techniques that were laborious and time consuming have become relatively straightforward in the digital darkroom. It’s easy to churn out digital photo compositions—and it has become more important than ever to create conceptual composited imagery that is interesting, unique, and hangs together with internal self-consistency. Greater ease of the compositor’s toolkit does not justify sloppy visual thinking.
Photo Compositing Steps in Photoshop
Figure 2: I created this composite image from three photographs: (1) The surf; (2) the sunset; and (3) an L-channel LAB inversion of red poppies.
Planning a composite before you start work is extremely important. You may not always end up exactly following your plan as work progresses, but you need to have a pretty good idea where you’re going. Without a clearly defined idea of your final image, you are likely to get images that don’t have clarity of purpose. It’s easy to go too far with compositing, and end up with imagery that is incoherent and scattered, and looks muddy.
Photo composite image conceptualization is a big topic, but to start with keep the following points in mind:
- Start with a clear idea about what you want your composite to convey. There should be nothing “mushy” in your concept.
- The best photo composites have “plausible deniability”—they may be unreal and impossible, but somehow they seem like they ought to be real.
- The different images that make up the composite should fit seamlessly together in terms of composition, color, intensity—and the lines and patterns in each image.
- Consider the direction of light in each of your component images—if it is not more or less the same, then the completed composite will seem jarring.
A good photo composite leads to suspension of disbelief on the part of viewer, just as someone reading a well-written story suspends disbelief. We know that the events described in the story—and the view shown in the composite—can’t really have taken place as they are shown, but we are pleased to collaborate in our own deception thanks to the seamless and authoritative nature of the work of art.
In contrast to the extreme difficulties involved in conceptualizing a good photo composite, the mechanics of putting together composites in Photoshop are not too tough—although the process can be time consuming.
The steps involved in creating a composite are as follows:
- Start with a clear conception of the image you’d like to create in your mind’s eye. As I’ve noted, the final image may in fact turn out differently than your pre-visualization, but without a starting idea it is very difficult to create a coherent composite.
- Gather the pieces of your composite in a single folder on your computer. Most likely, the composite will require photos that you’ve taken over time and are stored in different places in your archives. It’s smart to start by gathering these disparate images and placing them in one new folder that will be dedicated to the process of compositing.
- Resize and/or rotate individual images so they will properly fit in your composite. Depending on the techniques used, this part of the process may come before or after the image is added to the layer stack (nominally Step 4).
- Arrange the pieces of the composite in a layer stack.
- Use layer masks to “paint in” the appropriate portions of each photo that will be seen in the final composite.
- Archive the layered version of your composite, and then merge down the layer stack.
- Use the Clone and Brush Tools to add finishing to the photo composite to make sure the different images have been properly integrated.
There’s no better way to learn compositing than to try it and to experiment with creating composite images.
I’ve briefly discussed conceptualized and planning your photo composite in this section. In the remainder of this article, I’ll explain the basics of the other steps in creating a Photoshop composite so you can do it on your own.
Figure 3: In this photo composite, a nude woman in transparent material that is almost like a bridal veil seems to rise from a winter landscape. I created this composite from a studio figure study of a model and three photos taken in Yosemite during the winter time.
Compositing an Image with Itself
Before I get to the specific steps involved in compositing, it’s worth noting that an image can be composited with itself. One may be the loneliest number, but not when it comes to photo compositing! Extremely attractive images can be created by compositing together variations created from a single image.
For example, I call the abstract composition shown in Figure 4 Grills Gone Wild.
Figure 4: The abstract photo composite was created from a single photo of a car grill.
You may be slightly surprised to learn that the photo composite shown in Figure 4 was created from the single shot of a vintage car grill shown in Figure 5. To create the final composite I prepared a number of LAB color variations of the original photo, resized and rotated these versions, and composited them all together.
Figure 5: This shot of the reflections in the chrome grill of a vintage car was the only component of the abstract photo composite shown in Figure 4.
While it’s relatively unusual to create an abstract photo composite from a single image, compositing an image with a rotated or resized version of itself is a time honored and hoary technique often used to salvage photos used in advertising or other media.
Gathering Images and Preparation
The image shown in Figure 6 of a flower reflected in the pupil of an eye is an example of a pretty simple photo composite—easier than most because it’s pretty straightforward to paste any photo with a dark background onto the dark pupil of an eye.
Figure 6: This flower reflected in the pupil of an eye is a simple example of an effective photo composite.
In actual fact, I started with the concept of something reflected in a pupil—but I wasn’t sure what the something was going to be. I tried flames, and then a skull, and then I hit upon this flower—which clearly was more visually effective than the other motifs. Sometimes you just don’t know until you try.
I gathered the files I wanted to use to create this composite in a folder, as shown in Adobe Bridge in Figure 7. This folder became the working folder for the project, with a variety of versions, experiments, and alternates as the process of creating the composite advanced.
Figure 7: I gathered the files I was going to use to create a composite in a single working folder.
The original flower image is shown in Figure 8. Incidentally, this image was created using a flatbed scanner rather than digital photographic capture with a camera.
Figure 8: The purple flower image was created starting with a scan.
Here’s the shot of an eye that I used (Figure 9).
Figure 9: The original shot of the eye.
Before I started compositing, I color corrected the eye photo a bit. I also decided to lighten the retina area of the eye and darken the center of the pupil. An almost entirely dark version of the pupil would make compositing very easy. Figure 10 shows the tweaked version of the eye photo.
Figure 10: The enhanced version of the eye photo shows more colors in the pupil, with the center of the eye darkened to black.
The first act in officially creating a composite is to place one image on top of another. It’s really easy in Photoshop to place one photo on top of another, creating a layer stack. With the Move Tool selected, click the image you want to drag on top, and pull it over the bottom layer. You’ll now have a two-layer composite, as shown in Figure 11.
Figure 11: The flower has been dragged on top of the eye.
Note: Before dragging an image on top of another, you should check to make sure that both images are in the same color space (e.g., RGB) and both have the same bit depth (e.g., 8-bits or 16-bits).
The only trick to placing one image on top of the other is positioning, which is hard to achieve because the opacity of the top layer hides where it is positioned on the lower layer. To overcome this hurdle, simply reduce the opacity of the upper layer to about 50% using the Layers palette as shown in Figure 12.
Figure 12: The opacity of the top layer has been reduced to 50% so you can see what you are doing when you position the top layer.
With the opacity of the top layer reduced, it is easy to precisely position the flower as you can see in Figure 13. Once you are happy with how the layers are aligned, you can boost the opacity of the top layer back to 100%.
Figure 13: With the opacity of the top layer reduced it is easy to align it precisely.
The workflow sequence in this article assumes that I’m resizing the top flower layer after I’ve moved it on top of the background eye layer. This makes sense when you are making the upper layer smaller.
However, if you needed to make the upper layer larger than its original size, this should probably be done before moving the upper layer. For any kind of substantial size enlargement, I recommend using either onOne’s Genuine Fractals plugin, which does an excellent job or the S.I. Pro interpolation action from Fred Miranda Software.
Sizing and Resizing
You can resize an image before moving it on top of the background layer using the Image > Image Size dialog. As I’ve noted, if you are resizing to make an image substantially larger you should use Genuine Fractals or S.I. Pro. These methods require calculation and a level of arithmetical engineering that is often difficult to accurately achieve without a plug-in when it comes to making images significantly larger. (There are also resolution issues involved in making an image larger, or up-sampling, but that is the subject of another column.)
If the image you are resizing is going to only be a tiny bit larger or (as in this example) is smaller, then I find that it’s far easier to start by selecting the layer you want resize and then choosing Edit > Transform > Scale. You can now simply eyeball how you want to resize the image by moving one of the corner handles provided as shown in Figure 14. Once again, to see what you are doing you’ll need to temporarily reduce the opacity of the layer being resized. If you want to proportionally resize the image, hold down the Shift key while you drag the resizing handle.
Figure 14: You can resize a layer by eye by dragging the handles at the corner of the rectangle.
It’s often necessary to rotate one of the component images in a composite to make the image fit correctly. Rotating by eye works the same way as scaling (resizing). Choose Edit > Transform > Rotate. As shown in Figure 15, you can now drag the corner handles to achieve whatever rotation you’d like.
Figure 15: You can rotate a layer by dragging the handles.
Tip: When you are resizing an image that you need to rotate, you can Control-click (Mac) or right-click (Windows) to bring up a context sensitive menu that quickly lets you change to rotation mode. This works both ways: you can just as easily change from rotation to resizing.
Much of the true craft of compositing comes when creating the layer mask, which determines how the layers are visually combined.
A completely white layer mask shows the entire layer (and hides the layers underneath). A completely black layer mask hides the entire layer (and shows the layers underneath). Areas in a layer mask that are neither completely black nor completely white partially reveal the associated layer.
To start with, you need to choose which kind of layer mask you are going to use. This decision should be made depending on whether you are going to reveal or hide more of the layer the mask is associated with. To add a white layer mask choose Layer > Layer Mask > Reveal All. To add a black layer mask choose Layer > Layer Mask > Hide All.
In the case of the purple flower, resized it is a great deal smaller than the eye layer. Photoshop fills in the remainder of the flower layer (where there’s no image) with transparent pixels. Since the transparent pixels will not display in any case, it makes no difference how you mask them. Therefore we may as well use a white layer mask as shown in Figure 16.
Figure 16: The layer mask is a kind of diagram showing which portions of the upper layer in a composite are visible.
I used the Brush Tool, at varying levels of black and gray, to paint on the mask, using visual cues to see whether I was painting out the right amount of the flower layer. Again, you can change the layer’s opacity to get a better look at the impact of your painting on the mask.
By the way, to get a look at the layer mask itself, bear in mind that a layer mask is an Alpha channel. You can display the layer mask as shown in Figures 16 and 17 (as opposed to viewing the effect the layer mask creates) using the Channels palette by making the layer mask channel visible, and turning off the visibility of the other channels.
If you look at the details of the layer mask I created (see Figure 17) you’ll see that I made the center of the flower entirely visible, the area corresponding to the flower petals partially visible, and the area of the layer around the petals completely hidden (so this portion wouldn’t run over the edge of the eye’s pupil).
Figure 17: Looking at the layer mask close-up, you can see that the center of the flower shows through at 100%, while the petals of the flower are only partly visible.
The Final Touches
You’ve added images as layers to your composite, combined the layers using directives specified by layer masks, archived a copy, and flattened the resulting photo composite. It’s the rare composite that doesn’t need some more work to make sure that details are in alignment.
Before starting on this cleanup work, you should make sure you are working on a duplicate layer.
These final touches are most often accomplished using the Clone Tool or the Brush Tool, each applied directly to the duplicate layer.
Note: There’s essentially no retouching required on the eye and flowers composite, but don’t be misled. Most photo composites require anywhere from a small amount to extensive work at this stage.
With the advent of the digital era, photo compositing has come into its own as a powerful medium. Current practitioners have only begun to scratch the surface of what is possible using digital photos and Photoshop to create composited imagery. No doubt future years will bring us composited surrealism, composited fantasy, composited abstractions, and composited illustrations—to an extent that is almost impossible to imagine today. It’s very exciting to be at the frontier of an important new art form.
You can learn more about the in-depth specifics of photo compositing in my book The Photoshop Darkroom: Creative Digital Post-Processing (Focal Press, 2009) and in my new book that is currently in the works The Photoshop Darkroom 2: Creative Digital Transformations (to be published by Focal Press in 2011).
This article explained:
- Conceptualizing a photo composite
- Steps in creating a photo composite in Photoshop
- Planning a photo composite using Photoshop
- Compositing an image with itself
- Gathering and preparing images
- Combining layers
- Sizing and resizing
- Masking layers in a composite
- Retouching using the Clone and Brush Tools
Other Photoshop Tutorials
Creativity in the Photoshop Darkroom by Harold Davis: Multi-RAW Processing | Creating HDR Images by Hand [Part I] | Creating HDR Images by Hand [Part II] | Sharpening in LAB Color | Converting to Black and White | Using LAB Color Adjustments
Harold is the author of The Photoshop Darkroom: Creative Digital Post-Processing (Focal), Creative Composition: Digital Photography Tips & Techniques (Wiley), Creative Night: Digital Photography Tips & Techniques (Wiley), Creative Close-Ups: Digital Photography Tips & Techniques (Wiley), Practical Artistry: Light & Exposure for Digital Photographers (O’Reilly Digital Media) and other books. Harold gives frequent digital photography workshops, many under the auspices of the Point Reyes National Seashore Association.
Text and photos ©2010 Harold Davis.
Text and photos ©2010 Harold Davis.