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Last Updated: March 2026
What is the Orbbec Gemini 305? The Orbbec Gemini 305 is an ultra-compact stereo vision depth camera specifically engineered for robotic wrist mounting and close-range precision sensing. Weighing just 68 grams with dimensions of only 42×42×23mm, this camera delivers sub-millimeter depth accuracy at 15cm and operates effectively across a range of 4cm to over 100cm. Unlike Time-of-Flight (ToF) cameras that rely on active illumination, the Gemini 305 uses passive stereo vision technology—similar to human binocular vision—to calculate depth through triangulation, making it ideal for applications where minimal power consumption and zero light interference are critical requirements.
Understanding Stereo Vision Technology
The Gemini 305 employs passive stereo vision technology, a depth-sensing approach that mimics human vision by using two synchronized cameras separated by a known baseline distance. This 18mm baseline enables the camera to capture two slightly different perspectives of the same scene, then compute depth information through geometric triangulation. The key advantage of this approach is that it requires no active illumination—no IR projectors, no laser emitters, no structured light patterns. This results in significantly lower power consumption, reduced heat generation, and immunity to interference from other light sources in the environment.
For robotic applications, this passive approach offers distinct benefits. The camera won't interfere with other optical sensors on the same platform, operates silently without visible or infrared light emission, and maintains consistent performance regardless of ambient lighting conditions. The Orbbec engineering team optimized the Gemini 305 specifically for close-range precision work, where traditional longer-range depth cameras often struggle with minimum distance limitations and accuracy degradation.
Comprehensive Technical Specifications
| Specification | Value |
|---|---|
| Depth Technology | Stereo Vision (Passive) |
| Baseline | 18 mm |
| Operating Range | 4 cm – 100+ cm |
| Ideal Range | 7 cm – 50 cm |
| Spatial Precision | ≤1% at 50 cm |
| Depth Resolution | Up to 1280×800 @ 30fps |
| Depth FOV | H 88° × V 65° × D 98° |
| Color Resolution | Up to 1280×800 @ 60fps |
| Color FOV | H 94° × V 68° × D 104° |
| Sensor Type | Stereo Color, Global Shutter |
| Latency | As low as 60 ms |
| Dimensions | 42 × 42 × 23 mm |
| Weight | 68 g |
| Interface | USB Type-C (USB 3.0/2.0) |
| Power Supply | DC 5V, 700 mA |
| Power Consumption | Average < 2.0 W |
| Operating Temperature | -10°C to +45°C |
| Protection Rating | IP54 (Dust & Splash Resistant) |
| Mounting | Bottom: 1×1/4-20 UNC, 2×M3; Back: 2×M3 |
| Multi-Camera Sync | Hardware & Software Supported |
| External Trigger | Software & Hardware |
Key Features and Capabilities
1. Ultra-Lightweight Design for Robotic Applications
At just 68 grams, the Gemini 305 is one of the lightest depth cameras in its class. This minimal weight is crucial for robotic wrist mounting applications where payload capacity directly impacts arm dynamics, power consumption, and precision. Whether mounted on a Universal Robots cobot, a Franka Emika Panda, or custom end-effector designs, the Gemini 305 adds negligible mass while providing essential visual feedback for manipulation tasks.
2. Sub-Millimeter Precision at Close Range
The Gemini 305 achieves sub-millimeter depth accuracy at 15cm distance, with spatial precision of ≤1% at 50cm. This level of accuracy is essential for precision assembly, small part manipulation, and quality inspection tasks where millimeter-level errors can mean the difference between success and failure. The 4cm minimum operating distance enables the camera to work extremely close to target objects—ideal for inspecting parts immediately before grasping.
3. Global Shutter for Motion Clarity
Unlike rolling shutter cameras that capture images line by line, the Gemini 305 uses global shutter sensors that capture the entire frame simultaneously. This eliminates motion distortion and rolling shutter artifacts when the camera or target objects are moving. For robotic applications involving dynamic motion, conveyor tracking, or vibration-prone environments, global shutter ensures consistent, undistorted depth measurements.
4. Low Latency Depth Output
With depth streaming latency as low as 60 milliseconds, the Gemini 305 provides real-time feedback suitable for closed-loop control applications. This rapid response enables robots to react quickly to changing conditions, adjust grasping strategies on the fly, and maintain precise positioning even in dynamic environments.
5. IP54 Environmental Protection
The IP54 rating provides protection against dust ingress and water splashes from any direction. While not fully waterproof like its sibling the Gemini 335L (IP65), this level of protection is sufficient for most indoor industrial environments, protecting against manufacturing debris, occasional cleaning spray, and dusty warehouse conditions.
6. Flexible Mounting Options
The Gemini 305 features versatile mounting options including a 1/4-20 UNC threaded hole on the bottom (standard tripod mount) plus M3 threaded holes on both the bottom and back surfaces. This flexibility enables easy integration into custom brackets, robot end-effectors, and existing mounting systems without requiring specialized adapters.
7. Multi-Camera Synchronization
For applications requiring multiple viewpoints or stereo camera pairs, the Gemini 305 supports both hardware and software synchronization. External trigger inputs enable precise coordination between multiple cameras, essential for 3D reconstruction, large workspace coverage, and redundant sensing configurations.
Comparison with Related Orbbec Products
Orbbec offers a comprehensive lineup of stereo vision cameras, each optimized for different use cases. Understanding how the Gemini 305 compares to other models helps in selecting the right camera for your specific application.
Gemini 305 vs Gemini 335
The Orbbec Gemini 335 is the closest sibling to the 305, featuring a 50mm baseline versus the 305's 18mm, and active stereo technology with IR projection versus the 305's passive approach. The 335 offers longer range (up to 20m) and works better in low-light conditions thanks to its IR projector, but weighs more at 97g and has larger dimensions (90×25×30mm). Choose the 305 for ultra-close precision work where weight matters most; choose the 335 for more general-purpose applications requiring longer range and better low-light performance.
Gemini 305 vs Gemini 335L
The Orbbec Gemini 335L is the long-range variant with a 95mm baseline, IP65 protection, and extended operating range (0.17–20m). At 133g, it's significantly heavier than the 305, making it less suitable for wrist mounting on smaller robots. The 335L excels in outdoor robotics, AMR navigation, and harsh industrial environments where the 305's lighter weight and IP54 rating would be insufficient.
Gemini 305 vs Gemini 2L
The Orbbec Gemini 2L features a 100mm baseline with active stereo IR technology and built-in IMU for motion tracking. At 152g, it's designed for larger robots and AMR applications rather than wrist mounting. The 2L offers superior depth accuracy at longer ranges (RMSE <2% at 4m) but cannot match the 305's close-range precision and minimal weight.
Gemini 305 vs Gemini 335Le
The Orbbec Gemini 335Le is an industrial-grade camera with IP67 protection, PoE support, and a rugged M8 connector. Weighing 220g, it's built for outdoor delivery robots, agricultural machinery, and harsh industrial environments. The 335Le's robust construction and extended temperature range (-10°C to 50°C) come at the cost of significantly higher weight and size compared to the compact 305.
Gemini 305 vs Gemini 435Le
The Orbbec Gemini 435Le represents the high end of Orbbec's industrial lineup, featuring configurable depth presets, Gigabit Ethernet with PoE, and exceptional long-range performance (up to 20m+). At over 1kg with its housing, the 435Le is designed for heavy industrial robots, forklifts, and large AMRs—applications where the 305's compact size would be insufficient.
| Feature | Gemini 305 | Gemini 335 | Gemini 335L | Gemini 2L |
|---|---|---|---|---|
| Weight | 68g | 97g | 133g | 152g |
| Technology | Passive Stereo | Active Stereo | Active Stereo | Active Stereo IR |
| Baseline | 18mm | 50mm | 95mm | 100mm |
| Depth Range | 4-100cm | 0.1-20m | 0.17-20m | 0.2-10m |
| Protection | IP54 | IP5X | IP65 | Indoor |
| Power | <2W | <3W | <3W | <3W avg |
| Best For | Wrist Mount | General Purpose | Outdoor/AMR | Navigation |
Primary Application Scenarios
1. Collaborative Robot (Cobot) Wrist Mounting
The Gemini 305 is purpose-built for mounting on collaborative robot wrists, providing close-range vision for pick-and-place, assembly, and inspection tasks. Its minimal weight preserves the robot's payload capacity and dynamic performance, while its close-range precision enables accurate grasping of small parts, insertion operations, and quality verification.
Popular cobot platforms compatible with the Gemini 305 include Universal Robots UR3e/UR5e/UR10e series, Franka Emika Panda, KUKA iiwa, FANUC CR series, and Omron TM series. The camera's USB-C interface and standard mounting threads simplify integration with these platforms.
2. Precision Pick and Place
For bin picking, small part handling, and precision placement tasks, the Gemini 305 provides the close-range depth data necessary for reliable grasp planning. The sub-millimeter accuracy at 15cm enables precise determination of part position and orientation, while the wide field of view (88°×65°) captures sufficient context for collision-free path planning.
3. Assembly and Insertion Tasks
Precision assembly operations such as peg-in-hole insertion, screw driving, and component mating require accurate relative positioning between the end-effector and target. The Gemini 305's close-range precision and low latency enable real-time visual servoing for these demanding applications, where traditional longer-range cameras lack the necessary accuracy.
4. Quality Inspection
The combination of high-resolution depth (1280×800) and color imaging (1280×800 @ 60fps) makes the Gemini 305 suitable for inline quality inspection. The camera can detect surface defects, measure part dimensions, and verify assembly correctness with the camera positioned close to the inspection target for maximum detail.
5. Humanoid Robot Hand-Eye Coordination
For humanoid robots and dual-arm manipulation systems, the Gemini 305 can be mounted on robot wrists or end-effectors to provide hand-eye coordination capabilities. Its lightweight design is particularly important for humanoids where arm mass directly impacts balance and power consumption.
6. Small Form Factor Mobile Robots
Compact mobile robots and tabletop automation systems benefit from the Gemini 305's minimal size and weight. The camera can be mounted on small manipulators, pan-tilt units, or directly on the robot chassis for navigation and obstacle avoidance in confined spaces.
Integration and Development
SDK and Software Support
Orbbec provides comprehensive software support for the Gemini 305 through the Orbbec SDK v2. The SDK supports Windows, Linux, and Android platforms, with APIs available for C, C++, and Python. Key features include:
- Point cloud generation with configurable resolution and filtering
- Depth-color alignment (D2C) for RGB-D applications
- Multi-camera synchronization for distributed sensing
- External trigger support for precise timing control
- ROS1/ROS2 wrappers for robotics integration
Hardware Interface
The Gemini 305 uses a USB Type-C connector supporting both USB 3.0 (recommended) and USB 2.0 fallback. USB 3.0 provides full bandwidth for high-resolution depth and color streaming, while USB 2.0 offers compatibility with legacy systems at reduced frame rates. The single-cable solution carries both data and power (5V, 700mA), simplifying cable management on robot arms.
Mounting and Mechanical Integration
The camera's compact form factor and multiple mounting points enable flexible mechanical integration. The 1/4-20 UNC thread on the bottom accepts standard tripod mounts and camera accessories, while the M3 threaded holes on bottom and back surfaces enable direct attachment to custom brackets and robot end-effectors. The symmetrical 42×42mm footprint allows for clean integration into square-profile robot arms and tooling.
Performance Characteristics
Depth Accuracy and Precision
The Gemini 305 achieves its specified ≤1% spatial precision at 50cm through careful optical design and factory calibration. Each unit undergoes individual calibration to correct for lens distortion, baseline alignment, and sensor characteristics. The sub-millimeter accuracy at 15cm makes the camera suitable for precision manipulation tasks where grasp success depends on accurate relative positioning.
Field of View Considerations
The depth field of view of 88°×65° provides a good balance between coverage and pixel density for close-range work. At the minimum 4cm distance, the camera captures a workspace approximately 7cm×5cm—suitable for small part manipulation. At 50cm distance, the coverage expands to approximately 90cm×65cm, enabling broader scene understanding while maintaining sufficient resolution for feature detection.
Environmental Performance
The IP54 protection rating enables reliable operation in typical industrial environments. The camera is protected against dust ingress (limited protection) and water splashing from any direction. The -10°C to +45°C operating temperature range covers most indoor industrial settings, though extreme temperature applications may require the more rugged Gemini 335L or Gemini 345Lg.
FAQ: Frequently Asked Questions
What is the minimum operating distance of the Gemini 305?
The Orbbec Gemini 305 can operate as close as 4cm from the target object, with the ideal working range being 7-50cm. This ultra-close capability makes it unique among depth cameras, most of which have minimum distances of 20cm or more.
How does passive stereo vision compare to active stereo or ToF?
Passive stereo vision uses ambient light and dual cameras to calculate depth, requiring no active illumination. This results in lower power consumption (<2W vs 3-5W), no interference with other sensors, and silent operation. Active stereo (like the Gemini 335) uses IR projection for better performance in low light but consumes more power. ToF cameras offer longer range but typically have higher minimum distances and are more susceptible to multi-path interference.
Can the Gemini 305 be used outdoors?
While the Gemini 305 can function outdoors in good lighting conditions, its IP54 rating and passive stereo technology make it primarily suited for indoor applications. For outdoor robotics requiring weather protection, consider the Gemini 335L (IP65) or Gemini 345Lg (IP67).
What is the difference between Gemini 305 and Gemini 335?
The main differences are: (1) Baseline: 305 has 18mm, 335 has 50mm; (2) Technology: 305 is passive stereo, 335 is active stereo with IR; (3) Weight: 305 is 68g, 335 is 97g; (4) Range: 305 is optimized for 4-100cm, 335 covers 0.1-20m. The 305 is ideal for lightweight wrist mounting and close-range work; the 335 is better for general-purpose applications.
Does the Gemini 305 work with ROS?
Yes, Orbbec provides ROS1 and ROS2 wrappers for the Gemini 305 through the OrbbecSDK_ROS1 and OrbbecSDK_ROS2 repositories. The camera publishes standard ROS messages including sensor_msgs/PointCloud2, sensor_msgs/Image (depth), and sensor_msgs/Image (color).
What mounting options are available?
The Gemini 305 features a 1/4-20 UNC threaded hole on the bottom (standard camera tripod mount) plus M3 threaded holes on both bottom and back surfaces. This enables mounting via standard camera accessories, custom M3 brackets, or direct integration into end-effector designs.
Can multiple Gemini 305 cameras be synchronized?
Yes, the Gemini 305 supports both hardware and software synchronization for multi-camera setups. Hardware sync uses external trigger signals, while software sync uses timestamp alignment. This enables applications requiring multiple viewpoints, stereo pairs, or 360-degree coverage.
What is the power consumption?
The Gemini 305 consumes less than 2.0W average power, significantly lower than active stereo or ToF alternatives. This low power consumption reduces heat generation and enables operation from standard USB ports without additional power supplies.
Conclusion: Is the Gemini 305 Right for Your Application?
The Orbbec Gemini 305 occupies a unique position in the depth camera market. Its combination of ultra-lightweight design (68g), sub-millimeter close-range precision, and passive stereo technology makes it the ideal choice for robotic wrist mounting applications where every gram matters and close-range accuracy is essential.
If you're building a cobot application requiring precise manipulation of small parts, developing a humanoid robot needing hand-eye coordination, or creating a compact automation system with strict weight constraints, the Gemini 305 delivers capabilities that larger, heavier cameras cannot match. Its $379 price point makes it accessible for prototyping and production deployment alike.
For applications requiring longer range, outdoor operation, or harsh environment tolerance, Orbbec's broader Gemini camera lineup—including the Gemini 335, 335L, 335Le, and 435Le—offers alternatives with different trade-offs between size, weight, range, and environmental protection.
Shop the Orbbec Gemini 305: Available now at OpenELAB
