Enhanced Camera Calibration
- David Avgikos
Before using DART MAX it must be calibrated. This is a quick process that aligns the enhanced camera’s view with the projected image so that shots can be accurately tracked.
Before proceeding, ensure that no sunlight is on the screen or wall with the projected image. DART MAX does not require a completely dark room, but you will get a more vibrant image (and calibration will be easier) if no lights are shining directly on the screen or wall where the projected image will be.
At this point, you should have your system hardware positioned and powered on. If not, you will need to do that before calibration. Refer to the Enhanced Camera Setup Guide for more information.
Step 1: Setup
If you have not already done so, start DART MAX by double-clicking the blue and white DART MAX icon on your computer’s desktop. In the DART MAX interface, click the Setup button so your laptop screen looks like the image below.
If you go to Setup and see a completely black or white screen, it means that the camera is not found or cannot be initialized. Check the camera button on the right side of the screen. If it is gray and reads “Camera Not Detected”, it means that the camera has not been found by the system. Exit the program, check your camera connection, and restart DART MAX. If it is blue and reads “Camera Initialized” the camera is connected and working properly.
Step 2: Position and Focus the Camera
The center area of the screen, outlined in green, shows what the camera sees. The camera should be positioned so that the image fits well within the green rectangle.
If your system is projecting a 13-foot wide image (the recommended size), the enhanced camera will need to be approximately 8 feet from the wall or screen.
The image above shows an ideal camera position with 1-2 inches of space between the projected image and the green rectangle.
The image below shows a camera positioned too close to the screen so that the image is cut off on the left and right sides.
Once the camera is properly positioned, make sure the image is in focus by adjusting the lens if needed. Ensure that you keep the entire projected image within the green rectangle.
You may need to rotate the tripod mount the camera is attached to to get it centered and straight. Do this by loosening the butterfly nut on the tripod and rotating the camera. Once the position is correct, tighten the tripod.
Step 3: Set the Area of Interest
The camera will capture information outside the projected image, including walls, windows, doorways, ceiling lights, etc. - all of which may give off light that could compromise calibration. The Area of Interest sets a boundary for the camera so that it does not process anything outside the screen area.
When the Area of Interest control is On, you will see a green box with eight adjustment handles similar to the image below. Using the mouse, move these handles until the area of interest is defined, as shown below. You do not want the Area of Interest to clip any part of the projected image, so keep some space between the projected image and the Area of Interest box.
Tip! Start with the corner handles first, then adjust the center handles if needed.
Step 4: Set the Camera Gain, Image Brightness, and Camera Threshold
Camera Gain, Image Brightness, and Camera Threshold work together to control the camera’s sensitivity to light. Between them, you should be able to calibrate your system in virtually any lighting condition. Although it is possible to calibrate the system in a brightly lit room, you should avoid sunlight or light falling directly on the screen.
In most situations, you will need to set the Camera Gain control to its maximum setting of 8. Use the Image Brightness control to adjust the brightness of the image. The precise setting will depend upon the lighting conditions in your particular room. Adjust the Image Brightness until the projected image is as bright as possible without being overblown. You should be able to differentiate the gray boxes seen in the bottom corners. In most situations, a setting of 50% will work.
The brightness of your projector has a direct influence on this step. Very bright projectors (more than 4,000 lumens) will require a lower Image Brightness setting than projectors with 3,000 lumens.
Camera Threshold is similar to a contrast setting that separates the white circles projected by the calibration function from the black background. Higher settings let in less light and are better for rooms with bright light.
As a general rule of thumb, the brighter your room is, the less bright you will need the camera to be. The darker the room is, the more you will need to increase Image Brightness. You can use the settings in the chart below as a guide.
Dark Room | Medium Lit Room | Bright Room |
|---|---|---|
50 Image Brightness | 40 Image Brightness | 30 Image Brightness |
40 Camera Threshold | 60 Camera Threshold | 90 Camera Threshold |
When DART identifies the white circles projected during calibration, it replaces them with red circles shown on your laptop screen. If the Camera Threshold setting is too high, some of the circles will be missing as shown below left. If the threshold is too low, you will see very large circles or “red noise” as seen in the image below right.
If needed, you can move the Camera Threshold slider during this phase of calibration until you see the correct number of red circles in the green area of interest. DART MAX will ignore any red circles outside the green area of interest.
Typically, more ideal lighting conditions (low to medium room light with no direct light shining on the screen) will use a lower Camera Threshold setting. Bright room light, including installations with light shining directly on the screen, will require higher Camera Threshold settings.
Step 5: Set the Calibration Grid Size
The system will project a grid of dots used to calculate screen size and camera distortion. There are two options, 8x8 and 16x16. For systems with the enhanced camera, you should select the 16x16 grid size, which delivers more accurate shot tracking.
Step 6: Run Calibration
Once the grid size has been set, you are ready to calibrate. Click the Run Calibration control to initiate the process. The computer will change the display as needed and when the process is complete, it will engage the IR cutoff filter inside the OptiTrack camera.
The title of the control will change based on the state of calibration.
Calibrated if the calibration process has been successfully run.
Not Calibrated if there is no calibration information stored or calibration was unsuccessful.
Working while the calibration process is running.
When calibration has been successfully completed, you will see a green grid projected similar to the one shown here.
Calibration Tips
Calibrating DART MAX is easy if you follow a few basic rules. The two most common problems during calibration are excessive room light and the camera position. If you are having difficulty calibrating the system, follow these guidelines.
Ideally, the screen size should be between 7 and 13 feet wide. This generally requires the projector to be 4-8 feet from the wall or screen.
Ensure that the projected image does not spill onto the floor or ceiling. If projecting on a wall, avoid light switches and electrical sockets as the shiny plastic cover can reflect light into the camera and interfere with calibration.
Do not project onto a whiteboard or other shiny surface.
Generally, the camera should be placed next to, or directly behind, the projector. The camera must see every inch of the projected image.
There should be little or no sunlight in the training room. Sunlight contains a lot of infrared light, which DART MAX uses to track shots fired from your training weapon. If you can turn off all the lights in your training room and you can still see, there may be enough sunlight to affect calibration and shot tracking. If your room has excessive sunlight, you may need to cover nearby windows.
Another lighting issue is any direct light source within the view of the camera. This may be a lamp or window - even an LED clock or power light on a computer. Remove any light source, other than the projector, that is in the camera's view. Also, watch for security cameras that emit invisible infrared light.
Watch for any bright light shining directly on the screen. This may come from overhead ceiling lights, track lights, or light from a window. Eliminate any harsh light from shining on the screen or wall.
Some security cameras emit a large amount of invisible infrared light. Ensure that cameras of this type are not pointed at the screen.