[ This article was first published in the May, 2009, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe. ]
Joyce Marcarelli sent me a note recently asking how to create a “light-emanating-from-a-lantern” effect.
Easy, I thought… use Light Rays.
Then, I tried it and discovered it was a lot more complex than I thought. So, I decided to turn this into a tutorial and share it with you.
To get started, here’s the effect we will create. You should replace the orange box with whatever graphic you wanted to generate the light — a lantern, headlight, porch light — whatever. In this case, I’m going to use an orange box because its simple.
Here are the steps.
1. In Final Cut, go to the Generator menu in the lower right corner of the Video tab of the Viewer, open the Generator menu and create a Square Shape. While you could use any shape, I like how square shapes add a stronger edge to a light ray.
2. Create at least two squares (you can use more, if you want a more complex light pattern) and stack them on top of each other — one on V1 and the other on V2.
3. On V3, I created another square to create the lantern. Or you can import whatever graphic you want to use as the light source and place it on V3.
4. Size, color, and position the V3 graphic (remember to double-click it to load it into the Viewer) as you wish.
5. If you are using a graphic with no alpha channel (that is, it is surrounded by a lot of black), apply Effects > Video Filters > Key > Luma Key. Set the Key Mode to Key Out Darker (this makes the black disappear) and adjust both the Threshold and the Tolerance so that the image looks perfect and the background has disappeared.
6. Turn off the green visibility light for V3 so we can see the layers below it.
7. Double-click the V1 square to load it into the Viewer. In the Controls tab, adjust the size and position so it is hidden by the image on V3 — you may need to turn on the V3 visibility light to see how the images align. In this case, I set the size to 8 and the softness to 2, just to soften the edges a bit.
8. Select the Timeline, then select the V1 and V2 clips. Apply Effects > Video Filters > Glows > Light rays. Double-click the clip to load it into the Viewer.
9. Notice the Center settings. I set the left box, which controls the horizontal position, way outside the image to get the long, streaming tail. Then, the right-hand box controls the vertical position, causing the light to stream up slightly. Vary these Center settings to get the light to stream in the direction and angle you want for your effect.
NOTE: You can keyframe the Center settings to get the position of the stream to change during playback. There are lots of ways to play with this, so give yourself some time to experiment.
10. I used the same image settings in the Controls tab for the clip on V2 – remember to double-click it to load it into the Viewer.
11. And the light ray settings that I applied to the V2 clip were similar, but I changed the vertical Center setting to allow the two streams to diverge.
12. Here’s the last, important, step. Since each track contains both the white light effect and an opaque black background, we need to make the black disappear. While this can be done with a key, a better way is to use a Composite Mode. Select the V1 clip and apply Modify > Composite Mode > Screen.
13. Then, select the V2 clip and apply Modify > Composite Mode > Screen. (Yup, its the same effect, you need to apply it to BOTH tracks.)
14. Finally, turn on the visibility light for V3 and look at the entire combination. The Screen composite mode combines just the lighter pixels in an image, and makes the rest transparent. It also gives us that nice highlight where the two streams overlap.
Thanks, Joyce, for asking the question. This is a nice way to learn about shapes, the light ray filter, and composite modes.
As with all effects, feel free to experiment and see what other effects you can create using these same tools!
