Flex 3

The Flex 3 camera offers integrated image capture, processing, and motion tracking in a powerful, compact package. Customize your camera with user-changeable M12 lenses, black case treatments, and OptiTrack’s exclusive Filter Switcher technology. Scalable, modular, and a fraction of the price you would expect—Flex 3 cameras deliver the world’s premier optical tracking value proposition.

Fast, precise, and efficient tracking

The Flex 3 is capable of capturing fast moving objects with its global shutter imager and 100 FPS capture speed. By maximizing its 640 × 480 VGA resolution through advanced image processing algorithms, the Flex 3 can also track markers down to sub-millimeter movements with repeatable accuracy.

On-camera image processing

The Flex 3 can send a variety of pre-processed image types to your PC, resulting in decreased bandwidth and CPU load, and more efficient motion tracking. Image processing types include:

  • Precision grayscale – Most precise marker detection. The Flex 3’s default processing type. Sends grayscale marker information to the PC for calculation of object location, size, and roundness using our most precise processing methods. Provides greater accuracy than other modes, but consumes more CPU resources and USB bandwidth.
  • Segment – Balanced marker detection. Similar to Precision Grayscale, Segment processing streamlines marker information for more CPU-efficient marker detection. Provides a balance between precision and USB bandwidth use.
  • Object – The most CPU-efficient marker detection. Provides more efficient USB bandwidth utilization, but delivers less marker information to the PC than other modes.
  • MJPEG-compressed grayscale – Full resolution grayscale frames, compressed on-camera for highly scalable scene video capabilities.
  • Raw grayscale – Full resolution, uncompressed grayscale.
Camera control

Access a variety of Flex 3 settings with any of OptiTrack’s software applications, such as the Camera SDK, for greater control over what your cameras capture and what information they report to the PC. Available settings include:

  • Image processing type
  • Frame rate
  • Exposure
  • Threshold
  • Illumination
  • Filter switching
  • Status LED control
  • And more…
MJPEG compression

New in the Flex 3, MJPEG compression consumes 1/10th the bandwidth of uncompressed video while still enabling real-time grayscale video at full frame rate and full resolution (up to 100 FPS and 640 × 480 with Flex 3 cameras). Compact, high-quality grayscale video enables image preview with multiple cameras, simultaneously–an indispensable tool for camera aiming and focusing during rig setup and calibration.

Grayscale video access

Access raw and MJPEG-compressed grayscale video to transform any Flex 3 into a high-speed scene camera. Simplify camera aiming and calibration, optimize skeleton configuration, provide live capture feedback, and improve post-capture cleanup with a variety of grayscale video options.

Calibrated scene video

Because Flex 3 cameras can operate in grayscale mode, any of the cameras in your volume can be transformed back into a scene camera after calibration, enabling scene video that has exact position and orientation relative to the tracking volume.

Improved skeleton definition

Once scene cameras are calibrated within the volume, you can visually preview potential flaws for a higher level of accuracy. Simply compare the calibrated scene video with overlaid points to confirm that the skeleton aligns with the actor’s body segments and corresponding markers.

Real-time tracking feedback

Monitor the relationship between the actor and skeleton to confirm accurate tracking or to quickly diagnose unexpected behavior. Grayscale scene video is particularly useful during facial motion capture, offering high quality previs for feedback and presentation.

3D overlay

Record MJPEG grayscale footage at up to 100 frames per second—4x faster than normal film playback speed. High-speed recording enables the correlation of scene video and tracking data on a frame-by-frame basis for precise analysis or cleanup in post.

Filter Switcher technology

Toggle your camera between capturing infrared or visible light with a single mouse-click. Swap your Flex 3’s 800nm pass filter out on the fly to access visible spectrum grayscale video for enhanced image quality whenever reference video is required.

Solenoid-driven, software-controlled

Flex 3 cameras are equipped with a solenoid that can be controlled in-software to extend or retract the infrared lens filter. OptiTrack’s custom polychromatic M12 lenses are specially designed to remain in focus in both the visible and infrared spectrums.

Enhanced scene illumination

Utilize environmental lighting—including standard fluorescent lights—to illuminate your scene for brighter lighting throughout large volumes.

Improved scene video recording and live presentation

Replace high contrast, infrared lighting with natural, visible light for more balanced and visually appealing scene video—ideal for presentation-quality streaming and recording.

Interchangeable M12 lenses

The Flex 3 can be optimized for a variety of applications with custom-designed, interchangeable M12 lenses. Choose between 3.5mm, 4.5mm, and 5.5mm EFL lenses to adapt your cameras to your ideal capture volume. All three lenses feature a special spring focus assist, very low distortion, and fast F#1.6 apertures for increased tracking distance. Typical applications utilize 3.5mm for capture volumes in smaller spaces, 4.5mm for larger capture volumes and camera counts, and 5.5mm for facial capture.

Compact design for low profile integration

Flex 3 cameras can be discreetly integrated into large installations, or allow you to spatially optimize desktop capture volumes for face mocap and tracking rigid bodies. Choose red camera cases for higher visibility, or black for subtlety.

Unobtrusive infrared light

Flex 3 cameras emit 850nm IR light, which is nearly invisible, for inconspicuous and gentle lighting, thereby avoiding vision fatigue and unwanted attention to your capture rig caused by cameras that emit bright, visible spectrum light.

High power strobe mode

When used with an OptiHub, OptiTracks’s custom high speed USB hub, Flex 3 cameras can operate in high power mode to draw additional power for the IR strobe. The extra power increases capture range and reduces marker dropout. The Flex 3’s standard power mode is USB power compliant for use with off the shelf hubs and direct connections to a PC.

OptiSync

OptiSync1 is OptiTrack’s custom synchronization system, which sends and receives sync signals over USB cable. As a result, cabling is reduced by 50%, which enables faster and simpler setup.

External sync in/out

Integrate Flex 3 cameras into large scale tracking and analytical ecosystems with external sync in and out. Utilize frame triggers or free-run triggering to synchronize frame cycling with external software controls and hardware components like force plates and shutter glasses.

V100 and V100:R2 compatibility

The Flex 3 includes backwards compatibility with existing V100 camera installations in traditional Wired Sync mode and V100:R2 installations in OptiSync or Wired Sync mode. OptiSync is only available for Flex 3 cameras connected to OptiHubs.

OEM integration

Incorporate Flex 13 cameras into custom vision or tracking applications via the free Camera SDK.

1. Only enabled with the OptiHub, Optitrack’s custom USB High Speed hub, designed to complement the Flex 3 camera.

Camera Body
  • Width: 1.78 inches (45.2 mm)
  • Height: 2.94 inches (74.7 mm)
  • Depth: 1.44 inches (36.6 mm)
  • Weight: 4.20 ounces (0.1 kg)
  • Mounting: 1/4″-20 tripod thread
  • Status Indicator: 2 digit numeric LEDs
LED Ring
  • 26 LEDs
  • 850 nm IR
  • Adjustable brightness
  • Strobe or Continuous Illumination
  • Removable
Lens & Filter
  • Stock Lens: 4.5 mm F#1.6
    • Horizontal FOV: 46°
    • Vertical FOV: 35°
  • Optional Lenses:
    • 3.5 mm F#1.6
      • Horizontal FOV: 58°
      • Vertical FOV: 45°
  • M12 Lens Mount
  • Adjustable focus w/ spring assist
  • 800 nm IR long pass filter
  • Optional: 800 nm IR long pass filter w/ Filter Switcher
Image Sensor
  • Imager Size: 4.5 mm × 2.88 mm
  • Pixel Size: 6 µm × 6 µm
  • Imager Resolution: 640 × 480 (VGA, windowed from 752 × 480)
  • Frame Rate: 25, 50, 100 FPS
    • Frame decimation (transmit every Nth frame)
  • Spatial decimation: 320 × 240, 160 × 120
  • Latency: 10 ms
  • Shutter Type: Global
  • Shutter Speed:
    • Default: 1/1000th of a sec. (1 ms)
    • Minimum: 1/50,000th of a sec. (20 µs)
Image Processing Types
  • Object
  • Segment
  • Precision Grayscale
  • MJPEG Grayscale
  • Raw Grayscale
Input/Output & Power
  • Data: USB 2.0
  • Camera Sync: USB 2.0 or Wired Sync
  • Power: USB 2.0
    • Standard: 5V @ 490mA
    • High Power: 680mA
System Requirements

Recommended system requirements can vary significantly based on camera model and count.

Note: Flex 3 cameras must be connect to the PC via an OptHub 2 in order for the LED Ring to be powered. Connecting the camera directly to the PC will result in the LEDs being disabled.
In the Box
  • 1 Flex 3 camera Part number: FL3
  • 1 Sync splitter cable
  • 1 Quick Start guide

More Information

Camera SDK
Camera SDK

Full camera control, access to 2D object data, camera syncronization, and comprehensive vector tracking – a complete assortment of tools…


Specifications and other information are subject to change without notice. All brand and product names are trademarks or registered trademarks of their respective holders. The information on this webpage is provided by the respective named manufacturer and is for general information purposes. These data constitute a concrete indication of properties and condition only if they are expressly indicated by EST or have been agreed upon as a condition in writing.

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