Carlo Bergonzi 1735 ‘Baron Knoop’ violin: Measure for measure
Rudolf Hopfner explains how the vast majority of measurements for The Strad ’s latest poster were taken from micro-CT scans of the ‘Baron Knoop’ Bergonzi
One of the main strengths of micro-CT scans is the ability to take precise measurements at any given point. This is particularly important when dealing with the bodies or heads of stringed instruments. On a violin body, the longest straight lines do not exceed 30mm. They lie on the ribs perpendicular to the plates, and even in this case the word ‘straight’ has to be taken with a pinch of salt. The taking of measurements of the arching with analogous means is especially tricky and can lead to divergent results. The use of CT scans offers solutions to at least some of these problems. Nearly all the measurements for The Strad ’s poster of the Carlo Bergonzi ‘Baron Knoop’ violin have been taken digitally. Only the total length and the neck length were measured with traditional tools because the body and head had to be scanned separately.
The data of CT scans is saved in the form of voxels, the 3D equivalent of pixels in the 2D domain. The size of a voxel corresponds to the resolution of the scan. In case of the head of the Carlo Bergonzi violin this is 0.10674mm…