How to do Optical Flow in DaVinci Resolve for Smooth Motion

What is optical flow

Optical flow is a popular video processing technique that analyzes the movement of pixels between frames. It makes new intermediate frames to generate slow motion, making it particularly effective for slow-motion videos. This method is popularly used in video editors, like DaVinci Resolve and CapCut.

Use cases of the optical flow effect

• Making smooth, slow-motion action shots: Optical flow generates extra frames in between the real frames, which create the effect of smooth motion to a fast-moving video when it is slowed down. This spatial processing prevents the jerky playback and conserves the motion clarity.
• Increase frame rate on newer devices: Optical flow is based on the ability to make lower-fps or legacy motion video playback smoother, increasing frame rate. This is ideal for sharing archival footage to then contribute to something in your project.
• Time remapping with cinema storytelling: Filmmakers use optical flow to manipulate time. (either slow or speed up a movie). The visual quality is traded off here for even more impact.
• Fluid transition in music videos and trailers: Optical flow enables creative transitions by maintaining continuous movement during cuts and jumps in frames. It improves the flow and rhythm, syncing visuals with music seamlessly.
• Improving VFX tracking in compositing workflows: Accurate motion estimation from optical flow enables the stabilization of shots and alignment of visual effects. It ensures that impacts, like objects or explosions, are locked to the moving elements.

These are just some applications of DaVinci Resolve. There are two methods of applying optical flow in DaVinci Resolve, which are discussed below.

How to use DaVinci Resolve's optical flow slow motion effect

Method 1: Slow motion with optical flow

STEP 1
1. Import your video clip

First, open DaVinci Resolve and go to the "Media" tab to import a video into the software. Alternatively, go to "File," then "Import," and finally "Media" to bring your video into the project. Drag the clip onto the timeline to start editing.

STEP 2
1. Retime controls

Right-click on the clip and select "Retime Controls" to open the speed adjustment panel. This allows you to slow down or speed up specific sections of the clip.

STEP 3
1. Adding speed points

Right-click on the video in the timeline and add different points at the start and the end of the section you want to slow down. Adjust the percentage to lower values, such as 25% for slow motion.

STEP 4
1. Apply Optical Flow

To apply optical flow in DaVinci Resolve, go to the "Inspector" panel. You can also right-click on the clip and select "Retime and Scaling," then "Retime Process," and finally select "Optical flow." For better results, set the motion estimation to "Enhanced Better."

Method 2: Slow motion with BCC Optical FlowSet up your project

STEP 1
1. Set up your project

To begin, import your project into DaVinci Resolve and drag it onto the timeline to start editing. Ensure that the Boris FX plugins are installed and available.

STEP 2
1. Add BCC Optical Flow

In the "Effects" library, select "Open FX," choose the BCC Optical Flow option and drag it onto your clip in the timeline.

STEP 3
1. BCC Optical Flow Settings

Open the "Inspector" panel and go to the "Effects" section. fine-tune different parameters, like blur level, velocity, and input frame rate, to enhance the slow-motion effect.

STEP 4
1. Render and Export

Once you are satisfied with the final output, navigate to the "Deliver" page and select your desired export settings. Finally, click "Add to Render Queue" and then "Start Render" to begin the export process.

DaVinci Resolve is an excellent tool for creating the optical flow effect. However, it can be complex for beginners. If you're looking for a beginner-friendly tool to create the optical flow effect, consider CapCut.

Easier alternative: Create an optical flow effect using CapCut

CapCut is a versatile video editing software, known for its powerful editing features. It is also an excellent tool for creating the optical flow effect. It offers features, such as a dedicated "Optical flow" tool with adjustable frame rates, allowing you to make the perfect optical flow effect. You can also enhance your video with a variety of visual effects, like filters, effects, stickers, and animations. So, download CapCut today and use its optical flow tool to create smooth, slow-motion effects.

Key features

• Optical flow options: CapCut offers a dedicated "Optical flow" tool to create smooth, slow-motion effects in your videos by selecting frame rates, including 30 fps, 50 fps, and 60 fps.
• Adjustable frame rate: You can adjust the video frame rate from 24 fps to 120 fps before exporting videos.
• Variety of visual elements: Enhance your video with CapCut's advanced visual elements, including filters, effects, stickers, and animations.

Steps to use CapCut for creating the optical flow effect

STEP 1
1. Import the video

To begin with, open CapCut and create a new project. Next, click "Import" and select a video from your device. Alternatively, drag and drop the video onto the timeline. Once the video is on the timeline, it is ready for editing.

STEP 2
1. Apply the optical flow effect

Once the video is imported, click on the video to select it. After that, go to the "Optical flow" tool in the right-hand toolbar. Choose from various frame rates, such as 30fps, 50fps, or 60fps. Once the optical flow has been applied, you can further enhance the video using CapCut's various visual effects, such as filters, effects, stickers, and animations.

STEP 3
1. Export the video

Once satisfied with the final video, click "Export" in the top-right corner of the screen and select your desired format and resolution. Finally, click "Export" to save the video to your device.

Optical flow in Davinci Resolve and CapCut are both effective options for producing smooth, slow-motion effects. However, to achieve standout optical flow, you need to adopt specific strategies, which are mentioned in the following section.

Pro tips for using optical flow in DaVinci Resolve

• Use "Enhanced Better" for motion estimation: In the "Retime and Scaling" settings, select "Enhanced Better" for accurate frame blending. If you desire a simple workflow, choose CapCut's built-in "Optical flow" tool for a one-click effect.
• Don't apply too fast or erratic motion: DaVinci's optical flow can lead to ghosting in fast or chaotic movements, so it works better with smoother videos. CapCut handles this motion cleanly using adjustable frame rate.
• Always color grade after retiming: Ensure that you retime your frame first and then use color grading to avoid inconsistencies in the interpolated frames. CapCut's color grading tool lets you maintain the video's visual consistency.
• Zoom in to check frame artifacts: Closely check the slowed section to catch any distortions or warping introduced by frame synthesis. CapCut eliminates these errors by allowing you to generate frames up to 60fps using its optical flow system.
• Match project frame rate for smoother output: Ensure that the timeline and output settings align with the target frame to avoid stuttering. CapCut allows you to set the desired frame during export, resulting in consistency.

Conclusion

Optical flow in DaVinci Resolve is an effective way to create smooth, slow-motion effects, particularly suited for cinematic scenes and music videos. This article discussed how to apply optical flow in DaVinci Resolve using two methods: ordinary optical flow and using the BCC optical flow plugin. Follow the tips, such as using "Enhanced Better" for motion estimation, avoiding fast motion, and zooming in to check for frame artifacts to create a smooth optical flow effect. Although DaVinci is an excellent tool for applying optical flow, it is complex for beginners. Meanwhile, CapCut is a user-friendly tool that offers features, like a dedicated "Optical flow" tool with adjustable frame rates, allowing you to apply the optical flow effect with ease. Get CapCut today and utilize its optical flow effect to create captivating slow-motion videos.

FAQs

1
1. Can optical flow improve video stabilization?

Yes, optical flow can improve video stabilization by carefully analyzing the pixel movement between frames. It enables you to smooth out the shaky clips by creating consistent frame transitions. This is particularly beneficial in action scenes. CapCut provides optical flow to stabilize motion with just one click.

2
1. What's the difference between optical flow and motion vectors?

Optical flow calculates the precise pixel-level movement between the video frames. Meanwhile, motion vectors are simpler estimates, often used in video compression. So, optical flow is smoother and a better choice for making seamless slow-motion effects. Motion vectors are lightweight and less precise in terms of visual quality. CapCut offers high-quality optical flow effects with adjustable frame rates, making it ideal for creating slow-motion effects.

3
1. What causes ghosting in AI slow motion videos?

Ghosting occurs when the software incorrectly blends the frames, particularly in fast or complex scenes. This leads to blurry, pixelated, or double images due to mismatched motion estimation. It's common in optical flow when the subject moves quickly or the background changes significantly. CapCut minimizes the ghosting effect with the help of its excellent optical flow tool and adjustable frame rates for smoother motion.