Frequently Asked Questions
- Why does the experiment object disappear from view when setting video threshold levels?
The threshold is set too high. Use the slider bar on the video settings dialog box to lower the threshold level.
- Why does my graph data look "spiky" or form a line?
1) The threshold is set too low in video settings. Objects in the cameras' field-of-view, other than the object you wish to track, exceed the threshold level. In the video settings dialog box, lower the threshold level.
2) You may have an interfering object whose level is too close to that of the object you are tracking. Use Scan Line View and Object View in the video settings dialog box to locate and remove competing objects in each cameras' field-of-view.
3) The video may be saturated in various places causing color artifacts. If your viewfinder, for example, shows white in the middle of a red object, it has probably reached saturation and the exposure should be turned down. Set the cameras for shorter exposures (the viewfinders should look darker afterwards).
- I've tried all of the above to resolve problems with my data. What else can I try to improve the quality of my graph data?
Sometimes, under fluorescent lights that produce very little red, it can be hard to get good data. In this case, add incandescent clamp lights to shine on the red objects.
- Why can't I get good data using a projector as my display?
There are two common problems with using a projector:
1) If the projector shines directly toward the cameras, it is often difficult to obtain good data because of the high-contrast field and backlighting to the target.
2) The cameras' field-of-view may include colored objects or views that interfere with tracking the target over which the experimenter does not have control (such as an audience of people). In this case, reversing the orientation of the Front View may solve the problem. Go to Experiment/3D Camera Alignment and clear the checkbox for "Front View is Facing Cameras".
- Why is a straight line being displayed as a curved line when capturing experiment data?
Why is a circle being tracked in an "egg shape" when capturing experiment data?
These issues are caused by one of two factors: 1) the left and right video cables are connected to the wrong input on the 3D-Motion Video processor (VP01). Make sure that the left and right camera's video cable is inserted into the corresponding (left or right) input on the VP01; 2) make sure that each camera is set to widest field-of-view (fully zoomed out).