3D scanning: what it is, what it is for, and how to choose a scanner
3D scanning captures the shape of a real object as a 3D file by projecting a known light pattern and calculating distance from what the camera sees. The resulting mesh can be edited, measured or 3D printed.
How it works and the common technologies
Scanners fall into three main groups.
- Structured light — projects a pattern and reads its distortion; high detail, best for small and medium parts.
- Laser — sweeps a laser line across the object; copes better with ambient light, good on site and for large objects.
- Photogrammetry — computes a model from dozens or hundreds of photos; cheap, but less accurate and slow to process.
What people use it for
Four uses cover most customers.
- Reverse engineering — recreating parts that have no CAD file so they can be remade or improved.
- Quality inspection — comparing a produced part against the design to see where it deviates.
- Art and collectibles — scanning sculptures or hand-modelled pieces to rescale and reproduce.
- Person-fitted and dental work — capturing shape to make items that fit one individual.
How to choose a scanner
Choose by object size and the accuracy your work actually needs.
- Accuracy is deviation from true size; resolution is the spacing between captured points. They are different things.
- Small, detailed objects: a desktop scanner with a turntable.
- Large objects, vehicles, furniture or people: a handheld scanner.
- Weigh the bundled software too — aligning scans and repairing meshes takes longer than scanning itself.
Limits worth knowing before you buy
Shiny, deep black and transparent surfaces reflect or absorb the light so the scanner cannot read them; the standard fix is a removable scanning spray.
The output is a triangle mesh, not a parametric model — engineering work still needs rebuilding in CAD.
Deep cavities and recesses the light cannot reach come out incomplete, so you scan from several angles and merge.
Frequently asked questions
Can I print a scan directly?
Usually yes, after closing holes and tidying the surface, since scans often have gaps where the light could not reach.
Can a phone replace a scanner?
For shape reference or collectibles, yes. Accuracy is far below a dedicated scanner, so it is unsuitable for dimensional work.
How accurate are 3D scanners?
It varies by model; manufacturers state accuracy in the spec sheet. Compare that figure against the tolerance your work allows.
Do you offer a scanning service?
Ask at any branch — and we also 3D print from files you have already scanned.