Using Layers in Photoshop by Scott Burdick
When doing paintings from photos taken out in the field one doesn't have the same luxury as a studio painting where you can set up all the models and props exactly the way you'd like them. But the spontaneity and energy can often be even more dynamic, so let me go through one situation and explain how I've used the Layers option in Photoshop to deal with some of the challenges of combining several photos together for a painting reference.
Here are two photos I took in Namibia, Africa of a tribe of Himba people dancing. When I shoot photos like this that I intend to paint later, it is a little different than shooting something as a photographer might. The first thing you'll notice is that one photo is slightly darker than the other, which is because I had my Nikon SLR camera set to bracket every other shot a stop lighter. I do this to make sure I have enough information in my shadows and my highlights to paint from in a very contrasty situation like backlit sunlight.
The second very important thing when shooting a scene like this is to remain in exactly the same spot and just keep shooting for a while. I took about fifty photos in rapid fire from this spot for a few minutes and then moved around the dancers and took another series from a different angle, slowly working my way 360 degrees. If you just snap one shot and then move to another angle and snap another shot, you won't be able to combine any two photos into a painting since the lighting, perspective, and angle won't match. You have to think ahead and keep in mind the painting that is your final goal.
Here I've opened up two photos in Photoshop and arranged them so both are visible side by side. I like the photo on the left, except I'd rather use the pose of the central dancer from the right photo.
First, I select the Move Tool on the left toolbar -- if you let your pointer hover over any of the tools, you will see it's name show up in yellow. The (V) in brackets is telling you that you can hit the "v" key on your keyboard as a shortcut to activate the tool.
With the move tool activated, I left-click and hold the clicker down anywhere in the photo on the right and then drag the photo onto the photo on the left. When it is positioned where I want it, I release the left-click button.
Now I open my "Layers" palette (if it is not open already, click "Window" at the top of the screen, then "Layers" so that a checkmark appears next to it. This will open the Layers palette.) Notice that I now have two layers in my image -- like two paper photos stacked on top of each other. You can use many more photos in a numerous layers, but I'll stick to just one layer and a background image to keep it simple here.
Now that I have two images together, I can close the open window on the right, since I no longer need it.
With the top layer selected (you can tell which layer is selected when it is highlighted in blue) I click the little square with a white circle inside it at the bottom of the Layers menu to add a "vector mask" to the top layer (also called a Layer Mask). You will see a white rectangle appear next to the thumbnail of the top layer, which photoshop has labeled "Layer 1." Notice the little double-line around the white box that tells you it is selected. If you click the thumbnail to the left, the box will move to it, or if you click the background, it will be selected (as well as turn blue.) This lets you know which part of your image is active and what your tools will affect.
I know this doesn't make sense yet, but bear with me, the vector mask is the most important tool in the layers menu and one you will use constantly when compositing images.
With the Vector Mask selected (so the white square has a box around it) I click Select-All at the top of the Photoshop screen to select the entire vector mask (you will see a dotted line appear around the entire image in your main screen.
Now l go to the very bottom of my toolbar where there are some squares that represent my palette's foreground (the large square on the left) and background (square on the right) color. I want the background color set to black so I click the smaller two black and white squares above the large two squares to reset it to the default black and white, and then I click the bent arrow just to the right of that to switch the black square to the background.
Now I hit the "delete" key on my keyboard. Two things should happen here -- the top layer should disappear and the vector mask in your layers palette should turn black. This is basically how the vector mask works -- whatever in the mask is white will make the top layer opaque, and whatever is black will make the layer clear.
I click Select - Deselect at the top of the Photoshop window.
Then I select the brush tool from the tool menu.
You will see the brush icon show up at the top with some options. If you click the blue downward arrow next to the circle with the number beneath it, some more controls will show up that allow you to use the sliders to make the brush larger, smaller, or use a softer or harder edge.
Making sure that my vector mask is selected in the Layers Palette and that the foreground color is set to white, I start painting with my brush in the are where the boy is located on the top layer. Notice how the boy starts to appear as if by magic. I don't need to be too careful at this point, since I can easily click the curved arrow next to the foreground and background color square to switch them and then I'll be painting with black and can make anything I just revealed become transparent again.
Notice how a little white patch appears on the vector mask thumbnail in the Layers Palette.
As I continue revealing the dancer I want to use from the top photo, I sometimes zoom in, make my brush smaller or bigger, and switch back and forth between white and black to refine it.
Once I have the figure revealed, I click the blue pop-down arrow next to "Opacity" in the Layers Palette and change the value to 50%.
Notice how the top layer becomes transparent, allowing you to see what is beneath it.
In the Layers Palette I click the Layer 1 image thumbnail to make it active. Then I select the "move" tool again and left-click and drag the now-transparent dancer in the main image until I have the layer positioned exactly where I want it.
Then I put the opacity in the top layer back to 100% and see the result, continuing to refine the position of the dancer if needed. (You can even go to Edit-Transform-Scale if you needed to make the dancer smaller or larger to match the background photo, but this isn't needed here.)
To deal with the exposure discrepancy between the two layers I left-click Image-Adjust -Levels at the top of the screen (making sure the Layer 1 thumbnail to the left of the vector mask is still selected.) I pull the black slider on the left inward to the start of the peak, then slide the middle slider a bit to the right to darken the top layer to where I want it.
Now I select the Background layer in the Layers Palette and left-click Image-Adjust-Levels again to lighten the background image a bit and make the two match more closely. This time I move the middle slider of the Levels to the left.
At this point you can still see some white haloing around the main dancer, so I select the vector mask, the brush tool (with a very small size), and zoom way in to clean up the edges more (switching back and forth between white and black as needed/)
When I have things as good as can be using the layers, I click the little downward-pointing arrow at the upper right corner of the Layers palette to revel more options.
Here I click "Flatten Image."
Notice in the Layers Menu the layers and vector mask all combine into just one background image. Once you flatten your image and save it, you won't be able to go back to work on the different layers at a later date, so I usually save a version with all the layers intact before I flatten the image. You won't be able to save it as a JPEG so it will be saved a a .PSD in Photoshop's file format that supports saving layers. It will be much larger of a file, but it will allow you to go back to the layers if needed.
There are still a few artifacts of the two photos that I couldn't get rid of in Layers, so I used the "Clone Stamp Tool" to clean up the final bits around the main dancer.
Here's the final composited photo.
"Himba Dancers" oil, 30" by 40"
Here's a painting I did of this scene. I actually use five different photos when I composed this reference, so it was too complex to use as the example in this article, but all the techniques I showed you are the same as I used with it, just with many more layers!
Well, that is the very basics of layers! There are lots of more things you can do with layers (layer options, using different blending modes, Alpha Channels, advanced selection tools, etc.) but what I've shown you here is really what I use most often when simply compositing photos to paint from.
Back to thumbnails