Projector SetupStart DAVID by running “Start_ DAVID3_x64” from the USB flash drive. If you wish to update your software to the latest version, go to www.david-3d.com to download the most updated version. If you use 32-bit system (not recommended), run “Start_DAVID3”. x64 (from the desktop, taskbar, or Windows Start Menu). The DAVID-LASERSCANNER interface window will be opened upopen. On the left hand side: - Select "DAVID SLS-2" as your setup type.
- Set up the Screen ID so that the stripe pattern is shown on your projector. (usually 2)
- Choose the camera you are using for the 3D Scan.
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Scan Object SetupDAVID measures the image intensities along 3 horizontal and 3 vertical lines and displays them as red curves. It is very important to find good settings so that these red curves are well saturated. Regard those image regions that show the wave patterns: The red intensity curves must be sinusoidal and must not be over- or under-saturated. In other words, the red sine curve must not be cut off at the blue borders. (insert one or two sets of 3 images showing how redlines/sine curves work) Image image image To achieve the best result, please carefully adjust the following settings: Working Distance Place the scan object in front of the projector. Adjust the working distance Camera Setup- Remove camera lens cap (PLACE IN SLIDING DRAWER SO IT WON'T GET LOST)
- Place the scan object in front of the projector.
- Optionally place object on the turn table. It takes about 8-10 scans to capture the object in full dimension. It may be helpful to set your object to be scanned on a turntable (one is located in the lower area of scanning station) to ensure that the object is rotated about a single axis, which will be helpful later on during the align process.
- You should now see your object covered with the projected pattern within the DavidScanner interface
Now, carefully adjust camera regarding the following considerations: Expand |
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| Adjust the working distance by moving the tripod or object on table to make sure the screen projected from the projector covers the entire object, not less, not much more either. | (insert an image of a scan object with illuminated stripes on the body) Image Added Working Distance is the distance between the object to be scanned and the projector. | (insert an image of working distance)- Projector focus
Dial “focal ring” located on top of the projector to focus the projected stripped image on the scan object. Depending on your projector model, if the projector is perfectly focused, the fine lines between the projector's pixels may cause a fine noise in the scan. If that happens, we recommend to set the projection slightly out of focus. This will not reduce the scan quality. (insert an image of projector focal ring) Position of the camera
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| To adjust the location and angle of the camera, | loose loosen the thumbscrew on the bottom of the camera to slide it. In general, the angle of the camera should be set to 22 degrees. Position the camera so that the projected pattern on the object surface (nearly) fills the camera view. If the camera view shows much more than the scanned surface, you should reduce the distance between camera and object. | Fix the ball joint (where available). Adjust camera focus to get a sharp image Make sure the screws are tightened up once the location is adjusted. (insert an image of thumbscrew)
- Exposure time
The Exposure should be set to the same value as the frame rate of the projector (usually 1/60s), otherwise the camera image will flicker/pulsate when looking at the projection. Camera focus Adjust the aperture of the camera so that you will get a rather bright picture. Look at the camera image and watch the sharpness of the object and the sharpness of the projected black and white stripes. Dial the
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| Dial “focal ring” located on top of the projector to focus the projected striped image on the scan object.
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- Adjust camera focus to get a sharp image.
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- Camera brightness/ aperture:
The “Projector Brightness” slider in the software should be set to the maximum. It should only be reduced had a clean modulation is not possible in the following. Adjust the mechanical aperture. Consider only those areas in the camera image which show the regular waves. The displayed intensity curves (red) must be sinusoidal and may neither be undersaturated nor oversaturated. i.e. the red sine curve should be cropped at the blue lines. Note: if the curves are strongly flattened in the dark area without being close to the lower blue lines, the ambient light may be too strong. In this case darken the room. The Aperture dial on the camera has a scale f-stop from 16 to 1.4). Even for very bright condition (small objects), please avoid setting f-stop higher than 16. Otherwise the sharpness could be lost. If necessary, better reduce the value “Projector Brightness” in the software.
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- Adjust the aperture of the camera. To find the proper brightness, view the interface in DavidScanner and look at the red sinusoidal curves within the blue line regions. The red wave pattern should be as close to the blue lines as possible without being cut-off
- Once you are satisfied with the focus and exposure, then tighten the fixing screws.
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| - Once you have determined that your projector focus, the camera position and focus, and the aperture (red sine waves are close but not clipped by blue lines), all look good, then fasten everything down.
- Lock down the camera and project’s position by fastening all screws including projector, camera and camera slide. The camera lens dials can be fixed with their locking screws.focus
| . This will not reduce the scan quality. (insert an image of the camera dial lock)Calibration- . Use hand-force and do not over-tighten hardware.
- The next step will be calibration so everything mentioned above needs to stay in position for the remainder of the scanning process. However, the position of the tripod, it's height and angle may be changed after the calibration has occurred.
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Calibrate ScannerTo Calibrate the Scanner: - Set up the calibration corner
Carefully fix secure the glass calibration panels in a 90 degree angle with two fixing brackets. Handle with care. (insert an image of the calibration panel) Image Added
- Choose a Calibration Pattern Size
Choose a pattern size that best fit fits the scanned object. The pattern object/region to be scanned; should be slightly larger than the object/region to be scanned. For object sizes above ca.200mmgreater than 200mm across any one dimension, use the large 240 mm pattern on the back. Note: for startersFor beginners, the pattern should be folded inwards. Advanced ; advanced users can avoid undersired undesired reflections with an outwardly-folded pattern, if necessary.
- Remove the object and set from the scanning area. Set up the glass calibration panels and the scanner in front of each other, about the projector at the same distance as location where the object was previously placed so that the projection and camera image on your monitor are sharp. The camera image should show the projected pattern as large as possible. In addition, the The 6-rings and several other at least 15 points of the calibration pattern must be visible. The entire camera image should be filled with about 15 24 to 70 markers
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4. Depending on the size of the projection, enter the correct scale length in the “scale[mm]”. This scale is written next to the dot pattern on the calibration panel. Image Modified
5. Check the camera image The camera should not be able to see past the calibration panels. In the areas where the waves are visible, the red intensity curves must not reach the blue lines. If the object to be scanned is considerably darker than the white glass calibration panels, the sin sine waves will now be overdriven. Work with the “Projector Brightness” slider in the software totemporarily adjust the red waves for the calibration step. Image Added
6. Click “Calibrate” to calibrate the entire scanner. |