Beam Bench Docs

Calibrate the camera

Solve lens distortion. One-time setup per camera + lens combination.

Every camera lens distorts the image. Wide-angle lenses curve straight lines. Lens calibration computes the correction so straight things look straight after correction. This is step one before alignment.

What you need

  • A camera physically installed and visible in Beam Bench. See Install a camera.
  • A printed calibration target, a regular grid of dots or crosses with known spacing. A standard chessboard pattern works.
  • 10-15 minutes.

Steps

1. Print and place a target

Print a chessboard pattern (or similar regular grid) at a size that comfortably fills the camera's view. A 10 × 10 grid at 20 mm spacing is a reasonable starting point.

Lay it flat on the bed. Make sure the camera sees the whole pattern.

2. Open the Calibration dialog

3. Add calibration points

For at least 2 points (more is better, aim for 4-8):

  1. Click Add Point.
  2. Image X / Y: the pixel location of the point in the camera image.
  3. Ref X / Y: the corresponding location in mm on your printed target (e.g. the corner of the third square at 60, 80).

4. Solve

Click Solve. The metrics appear: Quality (%), RMSE (pixels), Scale, Rotation, Translation.

Quality above ~90% with low RMSE means good calibration. Below that, add more points and re-solve, or check that your point coordinates are correct.

5. Save

Click Save Calibration. The calibration is stored on the active machine profile.

Verify it worked

  • The camera image, after calibration, shows straight lines as straight (verify with a long ruler on the bed).
  • The Camera panel shows the saved calibration in its status.

When to redo

  • You swap lenses.
  • You change zoom on a zoom lens.
  • You change the camera entirely.

The calibration travels with the active machine profile.

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