Where the two rays actually meet
A top-down view of two cameras observing one point, with pixel noise re-triangulated 300 times. The scatter is the answer: wide parallax gives a tight dot, narrow parallax stretches it along the depth axis.
Try this
Hold the noise fixed and shrink the baseline. The cloud stretches without a single number in the setup getting worse.
Where this lab comes from
Structure from Motion, from Scratch: 47 Photos to a 3-D Temple in ~800 Lines of PythonHow overlapping 2-D photos become 3-D points and camera poses: SIFT matching, the essential matrix, triangulation, PnP growth, and sparse bundle adjustment, built from scratch with OpenCV + SciPy. The pipeline registers all 47 Middlebury temple views at 0.25 px mean reprojection error, next to COLMAP's 0.30 px on the same images. Worked examples, three interactive labs, and the reconstruction growing image by image.
More in cameras and geometry
- Focus, aperture and depth of field — Move the subject and watch the focus plane and the blur follow.
- Four ways a fisheye maps angle to radius — Plot r(θ) for the classical designs against a fitted curve.
- The scene, and what the camera sees — Orbit a 3-D scene on the left; the pinhole view updates on the right.