Here are some questions that we are asked frequently. If you require any further information or case studies on any of these topics, don’t hesitate to contact us.

What is laser scanning?

It is a technique using lasers, mirrors and cameras to record the surface features of objects. Archaeoptics use two different types of laser scanner to obtain a full spectrum of results.

1. Triangulation

   The mirrors move the laser over the surface, as the surface deforms the laser stripe the camera records the shape of the laser line. This allows the surface of the object to be recorded and stored on computer. This method is most useful for smaller objects. The Minolta Vivid 900 is a triangulating scanner.

2. Time of Flight

   An accurate stepping motor plays the laser over the surface. The scanner measures the time it takes for the laser pulse to exit the scanner, bounce off the object and return to the scanner. This gives the exact distance from scanner to object. This method is most useful for large objects. The Mensi GS200 is a time of flight scanner.

As we use both types of laser scanner, we can scan objects from hand-sized artefacts to entire landscapes and buildings.

Isn’t laser scanning expensive?

Laser scanning costs £1000 per day (industry-average), but if you compare it to the costs of the alternatives, such as illustration or TotalStation surveys then the price is comparable. Laser scanning datasets can be repurposed to provide multiple deliverables from a single site visit and has many more uses than simple drawing, photography or photogrammetry. As such, in terms of “measurements per pound”, 3D scanning is more cost-effective than other techniques.

Can I get the data into AutoCAD?

Yes, point cloud and mesh data can be loaded into AutoCAD. However, AutoCAD is not primarily designed to handle these massive datasets and performance may be sluggish. We can provide thinned, resampled and decimated datasets to suit AutoCAD usage as required. Our Demon3D software also enables you to preprocess much of the data before AutoCAD is required.

Is it the same as MRI (Magnetic Resonance Imaging) or X-Rays? Can you scan beneath the ground?

No. MRI uses massive magnets to align the atoms of you body and measure the resonance of these atoms to produce an image that penetrates the entire body. X-Rays use absorption of radiation to photograph internals. Sub-surface ground scanning is usually achieved with geophysical devices such as ground-penetrating radar or magnetometry. Laser scanning only records the surface.

What can I do with the data?

At it’s simplest laser scanning can be used to record the current physical condition of an object and produce 2D drawing from any angle and with a number of different lighting and rendering techniques. Advanced data users can also produce replicas to any scale or incorporate the data into websites, virtual museums or GIS systems. Over a period of time successive datasets can be used to monitor the deterioration of sculpture. For many examples please check out our gallery and featured projects. Our blog also has running information on projects we are working on.

Can you scan people?

Yes, but they have to keep as still as possible. The sculpture “Deus ex Machina” by Sebastian Boyesen was constructed by scanning two dancers. They were scanned at 0.5mm resolution, far higher than conventional full-body scanners.

Is there anything you can’t scan?

There are some surfaces, which so not scan particularly well, for example any transparent material such as glass, mirrors, water, and crystal. Very black surfaces such as jet also don’t scan well. Chaotic surfaces, such as hair, moss or sand also pose problems.. However, in most cases it is possible to modify the surface to make it suitable for scanning.

Also the laser scanner cannot penetrate where light cannot penetrate. If you can’t see in then neither can the laser scanner.

What’s the smallest thing you can scan?

The smallest thing we have scanned is a £1 coin, however the detail is not particularly well resolved. Our scanner is capable of a resolution of 0.17mm/accuracy 0.047mm (approximately the width of a human hair).

What’s the biggest thing you can scan?

In theory there’s nothing too large to scan. For instance datasets of the Moon and Mars exist. The largest dataset we have acquired is of Grimes Graves, a Neolithic flint mine in Norfolk. Over 3800 scans were acquired of this one context with a raw dataset size of over 1,000,000,000 points. In terms of physical size, we have scanned large areas of topography at high resolutions. We have also undertaken scanning on several large sculptures ranging from 10-20 feet in height.

Can you scan outdoors?

Both our laser scanners can be used outdoors. Triangulation systems don’t function well outside, but, over the years, we have developed techniques for capturing high-quality data in almost any weather and environmental conditions. Our St. Paul’s Cathedral project was undertaken on scaffolding, in winter during daylight hours, for example.

If you have any other questions that are not answered here, don’t hesitate to contact us.