Photoshop CS4 Compositing: Combining 2D and 3D, Part 1 of 3
In a previous series, I demonstrated how to combine multiple 2D images into a single composite scene. This new series will look at the 3D capabilities in Photoshop CS4 Extended, showing you how to add realistic-looking 3D elements to your scenery. Part 1 (this article) focuses on the photographic processes and raw workflow; parts 2 and 3 discuss creating and styling the 3D object for your scene.
As with most compositing workflows, the creative thinking for a combined 2D-3D image should start with your photography. Photographers are taught to consider taking extra shots of any subjects that inspire us. These extra images can incorporate different exposure values and apertures, different lenses and camera angles, and of course different times of day.
Let's extend this thinking to the process of compositing: If you know ahead of time that you're likely to be taking images from a specific shoot and integrating them with other shots or artwork in your portfolio, try to brainstorm a little bit as you're making your photographic rounds. Do platforms, streets, or other elements in your scenes lend themselves to blended compositions? If you see something that's a little unusual, that can be composed in a way that "makes room" for other images later in the process, take the shot! If you don't use that shot, ultimately you've lost nothing; but if the shot is useful for a composite, you've saved time and possibly a bit of spare change as well (because no stock images will be required).
For example, consider the background shot I chose for this series. While photographing landscapes in Hawaii, I stumbled on the interesting scene in Figure 1. It seemed likely that this unusual, almost geometric break in the cloud formation, combined with a view of the valley below, could create unique compositing opportunities. I snapped 15 or 20 pictures of this scene, to give myself multiple options.
Figure 1 I decided to photograph this scene many times, knowing that it might be used as the basis for a composite.
Returning to my workstation, I sorted through the images in Bridge CS4 and began to brainstorm a bit. What kind of "extras" could I use to create a more interesting composition? It didn't take long to figure out that a good play on this scene would be a sphere or other 3D object rising through the clouds, as if they were being parted by a force field or some other phenomenonThe X-Files meets Photoshop.
Once I had determined which creative direction to take, the first step was to process the background scene with Adobe Camera Raw (ACR) in a way that accentuated the clouds and sky, while downplaying some of the peripheral scenery. For starters, the image needed some tonal adjustments to brighten things, without turning the clouds pure white or overdoing the lighter ground clutter. I used a combination of Exposure, Recovery, and Fill Light adjustments to make these improvements.
Another necessary step was to take a bit of the green tinge out of the foreground. This was a high-altitude shot captured in the early afternoonnot an ideal time, but the clouds don't wait! Using the Temperature and Tint sliders, I made some minor adjustments, and then I finished off the corrections on the Basic panel by boosting the contrast a tad and modifying the saturation to suit the look I wanted. Figure 2 shows my basic settings in ACR.
Figure 2 When processing raw photographs, it's important to know the look you want to achieve. Sometimes it's easier to make pronounced tonal or color shifts in this part of the workflow, rather than doing it later in Photoshop.
The next step was to zoom to 100% and switch to the Details panel, so I could minimize any camera noise present in the clouds and sky. I set the sharpening amount to zero, so that I could see exactly what sort of noise I would need to handle. Typically, shots taken in broad daylight at low ISO don't have much luminance noise, so I made only a slight change to the Luminance slider, as well as a modest increase to the default Color slider setting of 25. If you're not sure whether you've fixed all the noise, zoom to 200% and take another look before you quit. The idea is to eliminate noise without making the image texture too soft.
The next step was to add a bit of sharpening to the foreground area nearest the clouds. The idea is to make sure that the areas closest to the 3D object will have a similar level of sharpness. Final tweaks to sharpness are often made at the end of the process; in this case, you're using ACR to create an approximation of the final look you want.
For shots like this, where you may have some minor noise remnants in the sky, it's best not to sharpen those areas. Clouds and sky don't have a lot of textural detail; beyond that, any remaining "noisy bits" will be amplified by sharpening them. To avoid this problem, hold down Alt/Option and move the Masking slider to the right until all of the sky and virtually all of the clouds are previewed as black. Figure 3 shows the Detail settings.
Figure 3 The Detail panel in ACR can be a big help in removing unwanted camera noise from low-texture areas such as blue sky or water.
The final correction I made was to crop in considerably from the sides of the image and crop up a bit from the bottom. This change was intended to focus attention on the cloud formation and remove distracting ground elements.
After I finished making the basic corrections to the raw image, I checked the Output Settings to ensure that they matched my intended medium. For example, if I'm going to print something, I generally output 16-bit to ProPhoto RGB (if I'm not handing off the files to other people, in which case I use Adobe RGB 1998).
Figure 4 shows the final image prior to further Photoshop edits and inclusion of the 3D orb.
Figure 4 Once the background image has been processed in ACR, it's time to bring it into Photoshop for further adjustments, before adding and styling our 3D object.