Thoughts & Ideas

Creating a Digital Background

I posted this image a long time ago on Smugmug, along with the instructions on how to create something very similar, but I never actually blogged about it. So, I thought I'd share it with you today.

First off, what is a digital background? A digital background is an image that is suitable for placing behind the subjects in an image; thus replacing the original background. The original background might be a green-screen, other studio backdrop, or some other scene entirely.

Digital backgrounds should be made to complement the subject, and not to draw attention to the background, so realism is important. The background also should be fairly blurry -- a little detail is okay, but sharp edges will quickly draw the viewer's eye away from the subject. Lighting also needs to be considered -- think about how the light is hitting your subject, and then duplicate the lighting on the background. Any mismatch between the background lighting and the subject's lighting will cause a disparity in the image that the viewer will definitely notice (even if they can't say why).

The difficulty with digital backgrounds is that you will need to cut out your subject from the original image -- so solid colored backgrounds work best for this. Photoshop has some excellent tools for extracting the subjects from the background, and with practice you can get the cut-out down to a few minutes.

How to create in Photoshop

You can create a very similar effect in Photoshop (or similarly capable editor) by following these steps:
  • Create a new layer of the desired size (you'll want one large enough for most of your images)
  • Render clouds on the layer; you'll end up with a black & white cloud layer.
  • Add a Gradient adjustment layer, selecting a darker brown to brighter brown. Keep the colors fairly close together so things keep their blurry look.
  • On the cloud layer, warp it several directions so that it isn't quite as obvious that this is only the cloud plugin...
  • Create a group and add both the adjustment layer and cloud layer to the group. Make sure the Gradient adjustment layer is on top of the cloud layer.
  • Duplicate the group.
  • Inside the second group, rotate the cloud layer and warp or resize to your heart's content.
  • Modify the second group's blend mode from "Pass Through" to "Luminosity".
  • Alter the gradient adjustment layer in the second group to a different gradient until you achieve an effect you like. You may also wish to try different blend modes.
  • At this point you have a flat background; now it is time to add some lights.
  • Create a new layer and make a circle selection in the area where your main light will point.
  • Fill the selection with white and de-select.
  • Next, apply a 250 gaussian blur.
  • And, repeat the blur.
  • Change the blend mode to "Overlay" and fiddle with the opacity until you achieve a pleasing effect.
  • If you desire the vignette, follow these steps:
    • Create a new layer
    • Create an oval selection that fills the image, and then invert the selection.
    • Fill the selection with black
    • De-select all.
    • Apply a 250 Gaussian blur
    • Adjust the opacity to suit.
  • If you desire simulated noise, follow these steps:
    • Create a new layer
    • Fill with black
    • Set blend mode to Screen or Linear Dodge
    • Add about 9% monochromatic uniform noise.
    • Apply a Gaussian blur of 1.4
    • Adjust opacity to suit.
  • If you want to adjust colors after the fact, add a "Photo Filter" adjustment layer. You can either select specific "filters" (like the Warming filter), or apply color filters.
The image above is available for free under the Creative Commons License (share alike). Attribution is appreciated but not required. Commercial use permitted.

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