Fun with lasers! PDFs linked to here show information extracted from a movie of the top and back of a Brothers Amati violin. The black lines on the still photos in the PDF are curtate cycloid curves generated with free CCycloid software, based on a very simple concept of best fit with the scans. Below is the original movie from which the PDFs were derived.
I now use a better process that shows the entire arching in one shot, more sharply defined. A post in March 2010 shows a simple test example of that, and I’ll be showing more examples using the new process in future posts. Since both of these scans, I’ve done many more and refined the process of fitting cycloids to the curves, gaining a whole new (and totally unexpected) understanding of how the Cremonese makers thought of arching that explains some other points of Cremonese construction. This new concept is how I now teach arching at my summer workshop in California.