¶ Camera Calibration Guide
¶ Why do cameras need to be calibrated?
Camera positioning essentially involves using image pixels to deduce the real-world physical location; calibration corrects lens distortion, determines pixel scale, and aligns the camera's orientation. Without calibration, pixel coordinates are virtual and cannot be converted to real-world positions, rendering positioning completely unusable.
¶ The principle of camera calibration and alignment
- Calibration: Corrects lens distortion, calculates the camera's internal imaging ratio (intrinsic parameters), and straightens distorted images;
- Alignment: Calculates the camera's position and orientation relative to the real world (extrinsic parameters), and aligns the camera coordinate system with the world coordinate system;
- Uncalibrated: The image is distorted or out of proportion.
- Misalignment: The camera's location is unknown, and the overall positioning coordinates are off-target.
- Only with calibration and alignment can the actual physical location be accurately calculated from the image pixels, thus enabling camera positioning.
If camera positioning is not accurate enough, we recommend using the factory camera parameters built into the device firmware first, and fine-tuning the camera to improve positioning accuracy.
If the results still do not meet your requirements after fine-tuning, or if the camera position has changed, calibrate the camera as needed.
¶ 1. Check the Camera Calibration Status
When you connect the laser engraver to Falcon Design Space for the first time, the software automatically reads the camera parameters built into the device firmware to calibrate the camera.
1. Turn on the laser engraver and connect it to Falcon Design Space on your PC.
2. In the Falcon Design Space workspace, click the down arrow next to the camera icon in the upper-right corner, then select "Camera Control" from the drop-down menu to check the calibration status.
When the status is "Calibrated", click the camera icon to capture an image for positioning.
If the positioning result meets your expectations, no additional calibration is needed.
¶ 2. Read the Factory Camera Parameters to Calibrate the Camera
In the Falcon Design Space workspace, click the down arrow next to the camera icon in the upper-right corner, then select "Camera Calibration" from the drop-down menu.
Select "Read Firmware" and follow the on-screen instructions.
¶ 3. Calibrate the Camera
¶ Before You Begin
- Software version: Falcon Design Space V1.9.0 or later.
- Calibration tool: Camera calibration card.
Note: Click "Start Calibration" to access the calibration page, where you can download the camera calibration card.
Check the following environmental conditions before calibration.
1. Make sure the lighting is sufficient: Perform calibration during the day in a well-lit environment to avoid image capture issues caused by insufficient lighting.
2. Keep the work area clean: If you are using a honeycomb panel, or if the base plate has noticeable stains or strong reflections, place a sheet of solid-color cardstock or a wooden board over the processing area.
3. Make sure the calibration card is flat: Keep the calibration card clean, flat, and free of curled edges. The flatter the card, the better the calibration results.
¶ Calibration Steps
1. Turn on the laser engraver and connect it to Falcon Design Space on your PC. Make sure the device is connected successfully before starting camera calibration.
2. Click the drop-down icon in the upper-right corner of the workspace, then select "Camera Calibration".
Camera calibration procedures vary by engraver model. Follow the on-screen instructions in Falcon Design Space to complete calibration.
¶ Camera Calibration for Small-Format Machines
Reference models: Creality Falcon T1C, Falcon A1C and Falcon T1. The Falcon T1 is used as an example below.
Method 1: Calibration Using an ArUco Calibration Board
1. Select ArUco Calibration and capture a single image with the calibration board centered.
2. Place the calibration board in the center of the machine bed, then click "Capture" in the grid cell on the right to capture an image.
3. After capturing images at all required positions, click "Next" to proceed to material placement. Once the engraving material is in place, click "Next" to proceed to the engraving coordinates step.
¶ Camera Calibration for Large-Format Machines
Reference models: Creality Falcon A1 / A1 Pro, Creality Falcon2 / Falcon2 Pro / Falcon2 Pro D. The Falcon A1 Pro is used as an example below.
Method 1: Calibration Using an ArUco Calibration Board
1. Select ArUco Calibration and capture images of the five grid positions.
2. Manually move the laser module to the upper-left corner to prevent it from obstructing the calibration board's field of view. Place the calibration board in the center of the machine bed.
3. Click "Capture" in the center grid cell to capture an image.
4. Place the calibration board at the bottom position and click "Capture" to capture an image.
5. Move the laser module to the lower-left corner, then place the calibration board at the top position to prevent the laser module from obstructing the board.
6. After capturing images at all positions, click "Next" to proceed to the alignment step. Refer to Section 4, "Camera Alignment," in this tutorial.
Method 2: Calibration Using a Dot Calibration Board
1. Select Dot Calibration.
2. Manually move the laser module to the upper-left corner to prevent it from obstructing the calibration board's field of view. Place the calibration board in the center of the machine bed.
3. Click "Capture" in the center grid cell to capture an image.
4. Place the calibration board at each of the other indicated positions and click "Capture" to capture an image at each position. The calibration board can be placed flush against the edges of the machine bed.
5. After capturing images at all nine positions, click "Next" to proceed to the alignment step. Refer to Section 4, "Camera Alignment," in this tutorial.
¶ Troubleshoot Camera Calibration Issues
The following troubleshooting steps apply to calibration using a dot-pattern calibration card.
1. Excessive Ambient Light Causes Glare and Image Capture Failure
Try the following solutions in order.
1.1 On devices that support this feature, adjust the blue exposure slider on the left, then capture the image again.
1.2 Move the calibration card to an area with less glare, then capture the image again.
Before moving:
After moving:
1.3 Use an object to block the overhead light strip, then capture the image again.
2. The Image Score Is Too Low
We recommend an image score of 50 or higher for better calibration results. An image score greater than 1 can also be used, but the calibration results may be less accurate.
If the score is too low, move the calibration card slightly toward the center of the image, then capture the image again.
Before moving:
After moving:
3. Shadows Obstruct the Image During Capture
When capturing the upper image, move the laser module to the lower-left corner to prevent it from obstructing the calibration card. Shadows on the calibration card may affect detection accuracy.
When capturing the lower image, make sure shadows do not obstruct the card.
¶ 4. Camera Alignment
1. Place the Material
1.1 Place a workpiece measuring at least 250 × 250 mm in the center of the engraving area, then close the protective enclosure. Depending on the light source, use a basswood board or a piece of kraft paper.
1.2 Select the material, enter the processing height, and click "Next".
Note: The processing height is the distance from the machine bed to the surface of the material. If a honeycomb panel is installed, the processing height is the combined thickness of the honeycomb panel and the material. If no honeycomb panel is installed, the processing height is the material thickness alone.
2. Engraving Coordinates
Click "Autofocus". Once focusing is complete, click "Frame" to check the engraving area on the material. When the position is confirmed, click "Start Processing".
After processing is complete, do not remove the material. Click "Next" directly to proceed.
Note: Disable the "Stop When Cover Opens" function in the device settings before opening the protective enclosure to inspect the framing area and adjust the material position. Close the protective enclosure during engraving.
3. Align the Camera
3.1 Click "Capture" to capture an image of the engraved alignment pattern.
3.2 Zoom in on the image, locate the pattern labeled 1, and double-click its center point. A red crosshair will appear.
Note: Use the mouse wheel to zoom in or out of the image, and hold down the left mouse button to drag the image. If the point is marked incorrectly, click "Reset" to clear the markers.
3.3 After marking pattern 1, zoom in on pattern 2 and double-click its center point. A red line segment will appear.
3.4 Double-click the center points of patterns 3 and 4 in sequence, following the specified order. Then click "Complete" to finish camera alignment.
¶ Troubleshooting Calibration Issues
1. The double-clicked point is outside the center of the calibration pattern.
2. The calibration pattern centers were not double-clicked in the correct order (1–4), resulting in an error message.
