Exact Metrology is proud to be a part of the restoration of Cincinnati Music Hall’s sandstone ornaments in Cincinnati, Ohio. The restoration includes ten finials atop gables and a sandstone lyre.

This project was undertaken by Friends of Music Hall, a volunteer-driven organization whose mission is to preserve, improve, promote and provide education about Cincinnati Music Hall, a National Historic Landmark. Thea Tjepkema, board member and historic preservationist is leading this restoration project on behalf of the Friends of Music Hall.

When the architect Samuel Hannaford designed Cincinnati Music Hall in the High Victorian Gothic style, he included a Gothic fleuron, or finial, on each of the eleven gables. Over the past 140 years, the original carved sandstone has deteriorated to the point that only portions of these important decorative elements remain.

Exact Metrology scanned the extant ornament pieces using the Artec 3D Leo scanner in HD mode. Produced by Artec 3D, a world-renowned developer and manufacturer of professional 3D scanners and software, Artec 3D LEO has a 3D reconstruction rate of 80 frames per second. This makes it the fastest professional scanner on the market. With its large field of view, Artec LEO can scan and process large objects and scenes quickly and accurately. In addition, the scanner features data acquisition up to 4 million points/second, with a working range of .35-1.2 m. The 3D resolution on this scanner is up to .5 mm and 3D point accuracy up to .1mm. Artec LEO can scan in sunlight, as well as capture dark and shiny objects. It uses advanced hybrid technology and texture tracking, so users can point at an object and shoot without needing to stick targets. With no need to connect to a computer or to plug in to a main power source, users can hold the scanner and walk around freely, scanning without the worry of wires or additional equipment.

Arya Design, a Cincinnati based custom casting company, specializing in historic restoration and architectural products, used Exact Metrology’s scanned images to create complete 3D models of the finials and lyre.

Restoring the ornament

The company focuses on custom mold making with exact parameters to meet the design and color that was once there. Their proprietary formulas increase overall compression strength, while replicating the look and feel of historic carved stone. Arya also makes additional architectural cast pieces for new construction for the exterior and interior of commercial and residential buildings.

Chris Lafferty of Exact Metrology commented on this project saying, “Exact Metrology used a handheld Artec LEO 3D scanner with high definition software to capture images of Cincinnati Music Hall’s sandstone ornamentation. Pointing the scanner at the existing finials and lyre, it used a grid of structured light technology to document their shape. Light bounced back at three million points per second, documenting even the chisel marks.”

Chris Rose of Arya Design concluded, “We are proud to partner with the Friends of Music Hall in creating the pieces needed as the literal “crown jewels” of an amazing historic preservation project.”

Restored sandstone ornament