How to Create Lightning Effects in Final Cut Pro

Stormy weather is a fantastic setting for many genre films; from horror movies to sci-fi action adventures, a thunderstorm can help set the mood. Unfortunately, filming in a thunderstorm isn’t the best of ideas, even if you can find one happening when you’re ready to shoot. However, final Cut Pro has several solutions available, and with a bit of time and patience, you can add thunder and lightning effects into your videos, let’s show you how.

Part 1: Adding lightning to your shots

Filming in a Thunderstorm is impractical and unsafe, but you can easily add a lightning effect to a pre-shot clip. Of course, for the best results, you’ll need a cloudy day and a steady shot, but once you understand the method, you’ll be able to plan your shoots accordingly.

Step 1: Adding the Lightning

For this effect, you’ll need your pre-recorded shot and a photograph of some lightning with a lot of contrast. We’re using Motion Arrays’ fantastic stock photo and video collection.

1. Place your background clip in a new timeline, and trim the desired length.
2. Place your lightning photo on top of the clip and position it to start at the point you want the first lightning flash.
3. Select the picture, and on your keyboard, press Control + D + 1 + Enter; this will shorten the image to one frame.
4. In the Inspector, adjust the scale and position of the photo to fit the background image.
5. In the Effects panel, search for Crop & Feather and add it to your photo; use the Inspector to remove as many of the edges as you don’t need and blend them into the background.
6. Adjust the Blend Mode from Normal to Add.
7. Click on the Color Board and choose Color Wheel from the drop-down menu.
8. Adjust the Saturation and Color of the Highlight, Midtones, and Shadows to fit the scene.

Step 2: Adding Atmospheric Lighting

Now you have your lightning flash in the background; you need to create a big light flash to sell the effect; this is where that cloudy sky helps.

1. Hold Alt and drag your background clip up to create a duplicate.
2. Adjust the length of the duplicate to match the single frame photo; make sure it sits below the picture and above the background.
3. Select the duplicate and go to the Inspector Color Wheels.
4. Boost the Highlights and Midtones and reduce the Shadows in the shot to create the look of the sky when the lightning flashes.
5. Search for Draw Mask in the Effects panel and add it to the Duplicate clip.
6. Draw on the screen around the lightning bolt, creating a masked area of highlighted sky.
7. In the Mask Settings, adjust the Feather amount to blend the edges.
8. Go back to the Color Wheels adjustments to finetune the coloring to suit the scene.
9. In the Effects panel, search for Glow and add it to the duplicate; adjust the Amount to suit the scene.
10. Duplicate the background clip a second time by holding Alt and dragging upward.
11. Select the first duplicate and hit Command + C on your keyboard to copy it.
12. Select the new duplicate and hit Command + Shift + V; select all the adjustments you want to copy and hit ok.
13. Trim the new clip to a single frame and place a few frames after the first flash; adjust the Mask to highlight a different part of the shot.
14. Add as many duplicate flashes as possible by copying and pasting attributes across your clips.

Part 2: Creating the Lightning Effects With Sky Replacement

Adding lighting to your shots is much easier than replacing the entire sky. On the other hand, matching the new sky with your photo can be challenging and requires a fair bit of color grading. Check out this handy guide for Final Cut Pro Color Grading tools.

Step 1: Removing the Sky

For the best result, you’ll need a clip with a lot of contrast between the sky and horizon, but it is easier if the sky is one flat color. Again, we’re using the incredible selection of lightning shots available at Motion Array.

1. Drag your clip to the timeline and trim it to the desired length.
2. In the Effects Panel, search for Keyer and add it to your clip.
3. Use the box tool to draw across the sky to remove as much of it as possible. 
4. Use the Keyer controls to finetune your effect until you are happy with the shot.
5. Place your lightning shot beneath the clip in the timeline and adjust the Scale and Position to fit your scene.

Step 2: Adjusting Color and Lighting

The lighting effect might look pretty cool, but it is essential to spend a little time adjusting the lighting and color of the environment to sell the effect.

1. Search in the Effects panel for Day into Night and add it to your foreground scene; make adjustments in the Inspector until you’ve achieved a look you like.
2. Go in the Color Wheels panel in the Inspector and adjust the levels for both the lightning and foreground scenes until you are happy with how they match.
3. Select the lightning clip and while holding Alt, drag it upwards to sit above the foreground clip.
4. Adjust the Blend Mode of the top layer to Add.
5. In the Effects panel, search for Gaussian Blur and add it to the top lightning layer.
6. Adjust the Amount as high as it will go, and the Blur Boost to around 8.
7. Adjust the top layer’s Opacity if needed to make the foreground more visible.
8. Play around with the settings to reach your desired look.

Part 3: How to add SFX to Bring It All to Life

Sound Effects are a fantastic way to sell any effect and make your scene more believable. Motion Array has a tremendous collection of royalty-free Thunder and Rain sounds you can use in your projects.

Unlike many other sound editing techniques, you want to create an offset between the visuals and sound. After all, lighting is always seen before thunder is heard, and the delay between the two indicates the storm’s distance.

When placing your thunder sound effects, always leave a space between seeing the lightning and the thunder sound. You will need to judge this based on how far the storm is from the camera or performer. You can also add a muffled effect and decrease the audio volume to make it sound like the storm is further away.

Creating visual effects takes a little time and patience, but with a wealth of stock footage and sound effects available to download, you can have your pick of assets to use. Learning to add lightning effects to your shots might seem like a niche skill you will rarely use, but the techniques we’ve covered in this tutorial can help you add various things to your images. You can even use the incredible Final Cut Pro Masking Tracker to add moving effects to your compositions; find out more with this handy guide.