Chroma Key: How to Create Digital Backgrounds
As I discussed previously, chroma key is one of the greatest instruments a photographer can harness, especially when they do not have the capacity to maintain or house a variety of backgrounds. Shooting on chroma key is only one step in the process of chroma key photography, though. While correctly shooting the chroma key is important, so is having a well composed digital background. Without a decent background your images are going to resemble that of a teenager who just discovered Photoshop. So I will show you how to create a basic muslin looking background in Photoshop.
1) Creating a universal size
If you’ve been a photographer longer than a week you probably know that there are several different print sizes, and if you’re a photographer who has actually used different equipment through the ages, you know that not every print or camera uses a single universal scale when shooting or printing. SO you will need to create a new Photoshop document with an easily manipulated size. In this demonstration, I created a 10in x 10in canvas with a 300 resolution.
2) Create some clouds
Select a portion of your image with the rectangular marquee tool. I did something along the lines of a fourth of the canvas area. Find the “Cloud” filter, and apply it. It should be located under your “Filter” menu, and under the “Render” sub-menu. Make sure your two selected colors are black and white before you do this. Use the Move tool to expand the rendered clouds to fill your entire canvas. Don’t worry about distortion that’s a plus.
3) Duplicate and hide the duplicated layer.
You are going to need two separate cloud layers, preferably the same, so right click on your cloud layer and select “Duplicate”. Afterwards, you will need to hide this layer until you are ready to work with it.
4) Create the Hotspot
You will first need to create a new layer and fill it with black. Move this layer underneath the cloud layers. Select the “Erase” tool and set its brush size to about 200px and its opacity somewhere between 85-89%. Select your cloud layer and erase a good area out of the middle, leaving only an small amount on the sides. Make sure you only do this once, since you want to leave a slight hint of the clouds in the middle.
5) Create the muslin effect
Unhide your second clouds layer (it should be above the layer you just erased). Set it’s blending mode to “Soft Light”.
6) Create a gradient adjustment
This layer will allow you to change the color of the background so you will not need to create several separate files. Create a new “Gradient Map” adjustment layer, and make sure it is above all of the other layers. Click on the gradient under “Adjustments” (double click the gradient layer to open the adjustment panel), to open the gradient selector. At the bottom of the pop-up box you can choose your colors and how they correlate with your background. In my example I replaced the black slider with a blue and adjusted the color midpoint until I got the look I wanted.
That’s all it takes to create a basic muslin looking background. If you want to create a truly awe inspiring background you can play with the look of the clouds, amount erased, gradient selector, and even try rendering some lighting effect.