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3D Scanning Technology Compared: Structured Light, Laser, Infrared, Photos

3D scanning6 min readUpdated: 10/2026

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Almost all scanners for makers work optically: they shine light onto the object and use cameras to evaluate how it comes back. The differences lie in the type of light. That determines how accurate, how fast and how robust a scanner is. Many current devices combine two methods in one housing.

Structured light (fringe projection)

A projector casts a pattern of stripes or dots onto the object. One or more cameras see how the pattern bends on the surface. From the angle between projector and camera, the software calculates the distance for each point. This method is called triangulation.

Because many points are captured at once, structured light is fast and forgives movement. It is the most common technology in handheld scanners. Ambient light can interfere.

  • White or blue light: Blue light is used for fine detail on small objects, for example with the 3DMakerpro Seal, which has an object range of 10 to 300 mm.
  • Infrared (NIR, VCSEL): Invisible light that dazzles nobody. That makes it well suited to people. Shining 3D specifies the infrared source of its Einstar as a Class 1 laser product, meaning eye-safe. Infrared scanners such as the Creality Otter Lite often have a large working distance and also capture large objects.

Blue laser lines

The scanner projects several thin laser lines, often in a cross or parallel arrangement. The cameras capture the lines very precisely. Laser scanners are regarded as the most accurate technology for makers. Revopoint and Creality state that their laser modes often capture dark and glossy surfaces without spray. Transparent and reflective parts remain difficult even for lasers. For the MetroX Pro, Revopoint states up to 0.02 mm, and Creality likewise up to 0.02 mm for the Raptor.

In return, laser scanners almost always need markers, small sticky dots that the software uses for orientation. For laser mode, Shining 3D writes: if the device does not detect markers, it does not emit laser lines. The working distance is shorter, usually 150 to 400 mm. Laser is less suitable for people. Pay attention to the laser class: for the MetroX, Revopoint specifies Class 2M for the laser projector.

Hybrid scanners

Many current devices combine laser for detail with infrared for large objects and people, for example the Einstar 2, the Creality PIKA or the Revopoint POP 4. You choose the mode depending on the object.

Photogrammetry

Here there is no projector of its own. The software calculates the model from many photos showing the object from different directions. This works with any camera and with smartphone apps such as RealityScan, Polycam or KIRI Engine. All3DP gives 50 to 1,000 images for this. Photogrammetry is the cheapest, but also the least accurate. It is better suited to artistic models than to precisely fitting spare parts.

LiDAR in the smartphone

iPhone Pro and iPad Pro have a LiDAR sensor that, according to Apple, measures distances up to 5 m. It measures the time of flight of light and is fast but rough. That is enough for rooms and large objects, but not for printable detailed models.

What accuracy figures mean

  • Accuracy is the deviation from the real part. Manufacturers’ figures are best values, mostly for a single capture under laboratory conditions. Across a large object the error grows. Some manufacturers therefore state a volumetric accuracy, for example 0.05 mm + 0.1 mm × length in metres for the Revopoint INSPIRE 2.
  • Resolution or point spacing says how densely the measuring points lie. Details smaller than the point spacing are lost.
  • According to Formlabs, inexpensive scanners are at roughly 0.1 to 1 mm, more expensive ones down to 0.02 mm. Only compare values that were measured the same way.

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