[ This article was first published in the September, 2006, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe. ]
France Chee, from the Trinity College Institute of Neuroscience (and how many times do I get to say THAT in this newsletter??), in Dublin, Ireland, writes:
I would like to apply a “fisheye filter to still image I have imported from Photoshop into FCP (I’m using FCP4.5 by the way).
OK, so I do this and have the fish eye effect move across my image in the pattern that I want but what I would like is the filter to effect to be in Red, i.e. the fish eye and the rest of the image where the filter is not distorting be the original color. Or something similar to this.
Essentially the effect I’m after is to have a distorting image with only the distorted region in say blood red and this gradually spreads with the movement of the fisheye.
Is this possible to do?
Larry replies: Yes, but it involves creating a traveling matte where you colorize a copy of the clip. Here’s an article that describes the process or creating a traveling matte — use this to get a better understanding of what we are doing: Using Traveling Mattes to Reveal Portions of an Image.
Now that you understand how to create a traveling matte, here’s one way to create your effect.
1. Start by putting your original clip on V1. In this case, I’m using a shot of three balloons.
2. Go to the Generator menu (lower right corner of the Viewer) and generate a Circle shape. (You can use any shape, I picked a circle based on your description.) You adjust its size in the Controls tab in the Viewer. Edit the circle onto track V2 so that it runs the same duration as the V1 clip.
3. Duplicate the V1 clip and put it on V3. This is the clip that will have your red effect. It must start at the same time as the V1 clip and have the same duration.
4. Select the V3 clip, now we need to create your red effect.
5. In this case, I applied Effects > Video filters > Distortion > Pond ripple to the clip and adjusted the settings as you see here.
6. Then, to change the color to red, I applied Effects > Video Filters > Color Correction > RGB Balance and adjusted the settings as you see here.
7. Here’s what the effect looks like so far. Now we need to constrain it so it doesn’t cover the whole image.
8. Double click the Circle on http://www.larryjordan.com/articles/lj_travel.html and scale it to the size you need for your effect. In this example, I scaled it to 25% of normal.
9. Select the Motion tab for the circle and apply Center keyframes to move it around the screen as necessary.
10. To restrict the effect just to the size and location of the circle, select Modify > Composite modes > Travel Matte Luma. Now, your red ripples will be exactly the size and shape of the circle and move where ever the circle moves.
You can use any shape, at any size, with any effect — however, they are all constructed the same way.
