The capture frame rate for each Vicon Vantage camera can be configured in the Vicon application software. The configured frame rate will also affect the field of view. Higher camera frame rates may make windowing of the sensor necessary, such that the sensor area used for capture is reduced in comparison to lower camera frame rates. For full details, see Vicon Vantage camera technical specifications. If you are using Vantage+ firmware or later, you can also select High Speed mode in your Vicon application software to increase the camera frame rate with little or no reduction in the field of view.
Another characteristic of the camera sensor is the image circle. This is the sharp circular image that the camera lens casts onto the sensor, as shown in the following image.
|Scroll Table Layout|
|Horizontal AOV:||2 x Tan-1 (18.43/(2 * 18)) = 54.22°|
|Vertical AOV:||2 x Tan-1 (18.43/(2 * 18)) = 54.22°|
|Horizontal FOV at 9m:||0.0183 x (9/0.018) = 9.15 m|
|Vertical FOV at 9m:||0.0183 x (9/0.018) = 9.15 m|
These formulae take into account only the optical components of the camera and lens, thus they calculate the maximum possible theoretical Field of View from this combination. Poor illumination of the volume by camera strobes, less than optimal aperture or gain settings, or poor marker surface quality might all reduce the FOV in which a camera can recognize a marker below this maximum theoretical level.
When using these formulae, note that for frame rates above the full-resolution rates given for Vantage cameras in Vicon Vantage camera performance comparison, the sensor area is reduced due to windowing, as described in Field of View.
The aperture and magnification affect the depth of field, that is, the portion of the image that has sharp focus. Immediately surrounding this area, there is a region in which the image remains in focus. Outside of this area, moving towards or away from the lens, the focus becomes progressively less sharp and the image appears out of focus. Thus, as the aperture and focal length decrease, the depth of field increases. Conversely, as the aperture and focal length increase, the depth of field decreases.
Camera lens filters
To optimize the performance of the Vantage cameras, each lens is fitted with an optical filter that attenuates wavelengths of light other than the narrow passband required to pass the light emitted by the light-emitting diodes (LEDs) from the Vantage strobe unit and reflected back from the markers to the camera.
When the cameras are used outdoors, try to position the cameras to minimize the ambient light as the filter cannot distinguish ambient light of the same wavelength as that of the strobe.