How To Create Car Headlight Beams in Photoshop

In the days of analog film, every professional cinematographer needed to know how to simulate a nighttime car scene while shooting in daylight with the aid of under-exposed film and blue lens filters. In the digital age Photoshop users can do all of this in post-production with greater control and at less expense. The technology has changed, but the underlying concepts used to create the illusion of a car idling at night remain the same. Now, however, photographers can create the headlights and the nighttime lighting at their desks.

Things You'll Need

• Adobe Photoshop CS4
• Digital photograph taken in daylight containing the front of a car in the top third of the frame with the bottom two-thirds filled with flat ground

Instructions

Day to Night

1. Open a car photograph in Photoshop and create a Levels adjustment layer. Name the new layer "night_levels."

2. In the adjustments panels set the highlight output levels to about 50 (depending on the photo you are using you may need to adjust this setting). Select the red channel and set its highlight output level to 75, and then select the green channel and set the highlight output level to 150. These adjustments create the look of dusk by darkening the image overall and adding a bluish tint.

3. Select the layer mask of the "night_levels" layer and use the lasso tool to create two long, cone-shaped selections on the ground starting in front of each headlight. You will need to create one cone, then press "shift" to add the second cone to the selection. The narrow portion of each cone should be nearest the headlights---starting, perhaps, two or three feet in front of the car. Extend each cone beyond the border of the photo.

4. Use "Select" > "Refine Edge." In the dialog box adjust the "Feather" setting to about 75 pixels and the "Contract/Expand" to -50%.

5. Select the Gradient tool and in the control bar select the "Foreground to Transparent" preset. Click in the preset area of the control bar to open the Gradient editor. Set the left-most opacity stop's opacity to 0%. Create new Opacity and Color stops at the 50% location of the gradient (directly between the two transparent stops). Set the opacity of the new Opacity stop to 50% and the color of the Color stop to black. Close the Gradient editor.

6. Starting at a point slightly above and directly between the cone-shaped selections, drag downwards while holding "shift" to a point slightly outside of the bottom of the image frame. This causes the headlight's illumination to fall off naturally.

7. Select the background layer and create a color balance adjustment layer above it. In the adjustments panel drag the yellow/blue slider toward yellow until the headlight selection area of the image resembles the yellowish color of real headlights.

Tips & Warnings

• Getting the cone-shaped selections right requires some trial and error both while drawing it and refining the edge. Use the Save Selection command to save different versions while experimenting.

• Make a few attempts when applying the Gradient tool, using "Edit" > "Undo" until you create a smooth, realistic light falloff.

• When finished with the beams, select the car's headlights, feather the selection edges, copy the selection to a new layer, overexpose them with an Exposure adjustment layer and tint them yellow with a Color Balance adjustment layer.

References

• Photoshop Classic Effects; Scott Kelby; 2004
• Photoshop CS4:The Missing Manual; Lesa Snider; 2008
• Photoshop CS4 Bible; Stacy Cates, Simon Abrams, Dan Moughamian; 2009