Vicon Valkyrie cameras strobe unit specifications
- Gisela Roberts
- Andy Roberts (Deactivated)
- Ben Freeman (Unlicensed)
The following topics provide technical specifications for the Infrared strobe unit that is available for the strobed Vicon Valkyrie cameras (VK26, VK16, VK8).
Valkyrie strobe units use surface-mounted LEDs and have an optional secondary optic; this enables you to best match the light spread to the field of view obtained with the focal length setting of the lens.
Camera strobe (shutter) durations
The following table shows camera strobe duration for different specifications:
| Maximum duration | Specification |
|---|---|
| 0.5 ms | at 150 Hz progressive |
| 0.25 ms | at 300 Hz progressive |
| 0.125 ms | at 600 Hz progressive |
| 0.0625 ms | at 1200 Hz progressive |
The strobe light-ring emits light once per video frame and is precisely aligned with the global shutter of the image sensor. The duration is controlled in the camera's strobe settings in your Vicon application software. The strobe intensity, which controls the duration of the light being emitted, can be adjusted in 1/1000 increments from zero through to the maximum allowed. When increasing the strobe intensity, remember that very fast motion produces more motion blur, so you may have to compromise between lens aperture and strobe intensity settings.
The total power drawn from the Ethernet switch is the sum of the power drawn by the strobe and the camera itself. At a constant strobe intensity setting, the strobe power taken is proportional to the frame rate. Up to 150 fps, the strobe duration can be adjusted from zero to the maximum of 0.5 mS. In order not to exceed the allowable total maximum power taken, the strobe duration is automatically reduced as shown in the above table.
At frame rates above 150 fps, there will be a corresponding fall in light output and therefore a possible reduction in the distance that markers will be seen.
Infrared strobe specifications
The following table provides technical specifications and performance indicators for Vicon Valkyrie Infrared (IR) strobe units.
| Component | Specification |
|---|---|
| Strobe active source (AlGaAs LEDs) | 22 |
| Wavelength | 850 nm |
| Strobe viewing angle (to half luminous intensity). Set by secondary optics | 54° and 72° |
| Time averaged irradiance (in W.m-2) | 69.65 (PoE+), 82.91 (PoE++)1 |
| Maximum power consumption (per camera) | 25W (PoE+) or 35W (PoE++), running at 150 fps, maximum strobe setting |
| RoHS compliant | Yes |
1 Given the following assumptions:
- Ideal overlap of radiation characteristics of array diodes
- IEC 62471-1 classification distance is 200 mm
- Ambient temperature is 25 degrees C.
- Low visual stimulus at 850nm
- Calculation is for >1000 seconds.
