Choosing the right depth sensing technology is one of the most important decisions in any 3D vision project. Each approach — Time-of-Flight (ToF), Stereo Vision, and Structured Light — has distinct strengths and trade-offs. This guide breaks down the key differences.
Time-of-Flight (ToF)
How it works: Emits modulated infrared light and measures the phase shift of the reflected signal to calculate distance.
- Strengths: Works in any lighting condition, compact form factor, global shutter, consistent accuracy across the field of view
- Weaknesses: Limited range (typically under 10m), lower spatial resolution than structured light, multi-path interference
- Best for: Indoor robotics, AR/VR, gesture recognition, access control
- Products: Orbbec Femto Bolt, LUCID Helios2, Azure Kinect DK
Stereo Vision
How it works: Uses two cameras to triangulate depth from parallax, similar to human binocular vision.
- Strengths: Works outdoors in sunlight, long range (up to 20m+), rich RGB data, lower cost, passive
- Weaknesses: Requires texture for matching, accuracy decreases with distance, baseline size affects compactness
- Best for: Outdoor robotics, autonomous vehicles, drone navigation, long-range perception
- Products: Intel RealSense D455, Stereolabs ZED X, Luxonis OAK-D Pro2
Structured Light
How it works: Projects a known pattern onto the scene and analyzes the deformation to compute depth.
- Strengths: Highest depth accuracy and resolution, excellent for small objects and fine details
- Weaknesses: Sensitive to ambient IR, limited working distance, slower capture times, typically more expensive
- Best for: Industrial inspection, bin picking, precision measurement, quality control
- Products: Zivid Two, Photoneo MotionCam-3D
Decision Framework
The best depth technology depends entirely on your application requirements. For many projects, the answer may even be sensor fusion — combining multiple depth technologies for robust, comprehensive 3D perception.
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