To configure your Vicon Valkyrie system, complete the following steps:
Adjust camera settings
Start your Vicon application software, ensure it is in Live mode and that a Camera view is displayed.
In the System panel, select one camera.
Notice that the Properties for this camera are listed at the bottom of the pane.
Have someone wave the calibration wand in the capture volume and ensure that you can see markers moving in the view pane.
Note the Grayscale Mode property. The default setting is Auto, which tells the cameras to send to the Vicon software all the centroid data for grayscale blobs it can circle-fit. If any grayscale blobs cannot be circle-fitted, the grayscale data is sent to the Vicon software so it can try to circle-fit the blobs.
Look at the Strobe Intensity setting. With a value of 1, the cameras send as much light as possible into the volume.
Zoom in to a marker by right-clicking and dragging the mouse. Notice how the pixels change as you lower the light (to view images from a grayscale blob, Grayscale Mode must be set to All).
Notice the Threshold property. It tells the camera how bright a pixel must be to be accepted by the camera. Zoom in to a marker and notice how the pixels change as you adjust the property.
Adjust the Strobe and Threshold settings so that you see only the 2D circular-shaped markers in your volume. Adjust the Strobe Intensity setting only as low and the Threshold only as high as needed.
camera focus and apertureSet
Place three markers in the middle and on the far side of the capture volume.
Holding the camera body, unclip the lens cover from the lens. Carefully unclip one side of the cover first, and then ease off the cover from the other side.
Leaving the focus on infinity (∞), close the aperture to as high an f-stop value as possible, so that you can still see the markers at the furthest distance required.
In general, it’s better to run with a low Threshold setting and more closed aperture, than a high Threshold and open aperture. (See Threshold in Adjust camera settings.)
For each camera, turn the aperture ring (the ring with the f-stops) until the aperture is fully open. Later you will turn the ring back, increasing the f-stop number and closing the aperture.
Focus and aperture rings on a Vicon Valkyrie camera
In the System panel, select all the cameras (Shift+click). In the Properties section at the bottom of the window, change Grayscale Mode to All.
In the System panel, select a camera. For each marker:
In the view pane, zoom in to the center of the marker.Valkyrie cameras are supplied pre-focused for typical motion capture use, so in most situations, no focusing is necessary. The following step (b) is applicable only if you need to re-focus the camera, otherwise, go straight to step c.
- If required, turn the camera focus ring (see above illustration) until the 2D image of the marker in the view pane is clear and sharp. As you rotate the focus ring, note that the marker images get smaller and then begin to get larger again.
Good focus is when the marker is at its smallest.
Note that, with the aperture fully open, the markers appear fully saturated, with very little grayscale gradation and some merging:
Adjust the aperture ring to change the amount of light that hits the image sensor. Turn the aperture ring to close the aperture and obtain good, clear images of markers even when they are close together.
If you turn the aperture ring too far, until the aperture is almost closed, the markers appear very small, lack any bright grayscale pixels and the circle-fitting is poor:
Adjust the aperture ring so the markers are not too small, and the center is just off-white (not fully saturated) when viewed from the middle of the volume:
For each camera, repeat Step 6.
When you are happy with the focus and aperture, to prevent the rings from moving, tighten the locking screws using your fingers.
Caution: If the locking screws are not sufficiently tightened, the weight of the lens can cause the rings to move. Ensure the locking screws are finger tight, but to avoid damaging the screws or the rings, do not over-tighten the locking screws and do not use an Allen key.
To replace the lens cover:
- Hook one side of the clips on the cover, then rotate the other side on, with your thumb overhanging the clip area for extra leverage.
- Supporting the underside of the lens, push firmly downward over the clip until it clicks into place.
- Check both clips are in place and the cover is correctly positioned over the lens.
Caution: To ensure the lens remains free from dirt and other contaminants and that the camera remains IP65-rated, keep the lens cover in position over the lens after installation.
In your Vicon application software, select all of the cameras and change the Grayscale Mode property back to Auto.
For information on the next steps, such as masking and calibrating the cameras, see the documentation for your Vicon application software.