CT scans of violins can yield important data for research, give unparalleled arching and outline information to violin makers, and are surprisingly beautiful.
The Strad3D study violins were scanned as 600 'slices', which can be viewed as individual cross-sections, as frames in a video journey through the violins, or assembled into a 3d geometrical model of the entire violin, which can be rotated and studied from any angle.
CT videos shown here include several views including:
AXIAL (a series of sections taken across the width, showing internal and external arching)
WOOD (transparent 3D projection showing internal densities)
SURFACE (an opaque 3dD projection, showing a solid surface)
NB.Some strange visual “artifacts” are apparent in the CT images, a result of scanning interference from metal parts such as fine tuners and tail-gut adjusters.
The CT Arches and Outlines still images are 'slices' at familiar reference points, and show the coordination between the visible outer arch and channel, and the interior contours, with the concave curves of the channel reflected in the convex interior, which has a classic bell curve shape. The rib outlines give a direct view of the underlying designs.
CT scanning (Computed tomography) uses the same hospital equipment that is safely used on people. The differences in density are indicated by variations in the light and dark images.
CT has proven invaluable to evaluate the condition and authenticity of collectable violins. (See Steve Sirr & John Waddle; Use of CT scanning for the detection of internal damage, repair and determination of authenticity in high quality violins, Strad3D)
Researchers have used the Strad3D CT data to create complex 'finite element' models, computer-generated 'virtual Stradivari' in which individual variables such as arch height or wood properties could be changed at will, and the resulting vibration changes simulated and studied. Even a simplified finite-element model can dramatically show the effects of structural changes, as demonstrated by University of Birmingham physicist Colin Gough.