By Roger (20 Jan 2014)
If you are learning to use Photoshop, there are some more advanced skills that come in handy, time after time. One of these is creating a composite when the original photo has some small thing that isn't the way you want it. This goes beyond a simple clone or content aware fill action to remove a photobomber from the background. Some of the easier composite work is replacing a sky or combining images to create a single image that you like better than the components.
WARNING: If you cry “Cheater!” when composites are discussed around the dinner table, this blog may not be for you. As both of us have stated before, we are not journalists who are forbidden to twist pixels to improve a photo. We've discussed why you want to get things correct in the camera, but it doesn't always do the trick, especially if the sky is a boring gray while you are taking a photo at a location you can't easily revisit. I am unbothered by doctoring pixels to improve the photo.
To prepare for this work, you need to keep yourself open to taking photos of skies, backgrounds, etc., when you are out and about on other photo missions. I am constantly shooting clouds, sunsets, or paths in the woods because you never know what you'll want down the road. You can also buy stock images for this kind of work, but that doesn't seem right to me. Yeah, I know, this might not seem consistent from someone who loves composites, but we all have to draw our own lines. All my composites come from photographs I've made.
Start with your normal post-processing and cropping on your base image before you go into Photoshop. You should also make any changes to the second image to make it match the base image as closely as possible in white balance. Here is the base image of a bridge near Fountains Abbey, one of the old Cistercian monasteries in England (opened in 1132). I was there in 2007, on an obviously overcast day.
You can see the sky definitely needs improvement. I chose a sky with clouds because the overall lighting in the scene is soft and even, as when you are out on a cloudy day. I wanted to match the lighting, so I couldn't insert a bright sunny sky.
There are thousands of Photoshop tutorials on the web to show you the specifics of each step. They are not difficult to master. I will give you my steps, but not the specifics or this would be a book instead of a blog.
Drag the sky image into a new layer over the base image layer (bridge). You now have a file with two layers, and all that is required is a layer mask on the sky image to allow the base image to come through. Here are the layers, showing the two images and layer mask after selecting for the original sky. The black of the mask conceals the sky image while the white reveals the sky. You can move the sky layer around until it is positioned where you want. The resulting image is much better.
You can also make a series of photos into one photograph. I do this when I have a series of photos that have individual parts I like, but they are in different photos. A tripod is your best friend here because it keeps the background stable. When I'm casually photowalking in Poland, however, I probably don't have my tripod with me. For this series in the old timesquare, I leaned against a trashcan to keep my shots consistent. These eight photos took almost two minutes to make, so use something that will keep you steady. They look pretty good at the thumbnail level, but, when you zoom in, you can see the minor differences in my framing.
There were too many people in the foreground of these images; I wanted delete some of them. The bird flew through two of my images. I really liked it in there, but two would have been even better, right? No problem.
Do your pre-processing one photo, in Lightroom or whatever processor you prefer, and synchronize that work on the other photos. Open all they photos as separate layers in one Photoshop file and make sure you align the layers, even if you took the series with a tripod. You can see the layer masks obscuring or revealing certain parts of the layers that add to the final image. The two birds in the final are actually the same bird moving through the top two photos. It was, of course, in different positions in the frame. For those layers, I masked everything except the bird.
This may look complicated, but it really isn't. If you can use layer masks, you can do this. Practice will help you learn how to better order the layers for speedier work. For example, I knew that the birds were all I wanted in those layers, so I moved them from the center of the series and put them on top two layers and made a quick mask that hid everything, but the birds. Be careful to not to get captured by the fun or you can lose lots of hours to this stuff. Here are a couple other composites. Have fun.