Skip navigation
Share this page
MCI Logo

The Konter Ukulele:

Imaging Helps Visibility of Historic Signatures


Konter Ukulele

Visible light image of the Konter Ukulele.


The Konter Ukulele, a part of the C.F. Martin & Co. Museum & Archives in Nazareth, PA, was carried to the North Pole on the 1926 Byrd expedition by Richard Konter, a ship's mate who accompanied Byrd. The instrument bears as many as 100 signatures including notable Arctic and Antarctic explorers like R.E. Byrd and Roald Amundsen, as well as significant political figures (e.g., Calvin Coolidge) and celebrities (Charles Lindbergh, Thomas Edison) of the day. The ukulele has a complicated and fascinating story and filling in more of that story may be possible by revealing more signatures. The MCI Imaging Studio was requested by Larry Bartram and Dick Boak to carry out non-invasive digital imaging of the ukulele with the objectives of increasing the legibility of the unidentifiable signatures.

In June of 2014, the ukulele was brought MCI for a day of imaging that included Reflected Infrared Digital Photography (IR), Infrared Reflectography (IRR), Reflectance Transformation Imaging (RTI), UV-induced Visible Fluorescence, Multispectral (MSI), and visible and infrared imaging details of the soundhole. The imaging was completed by E. Keats Webb with the help of Emma Tucker and Alicia Hoffman, National Science Foundation (NSF) funded Research Experiences for Undergraduates (REU) summer interns.

IR Image of Konter Ukulele

Reflected infrared digital image of the Konter Ukulele.

Reflected Infrared Digital Photography was done with a modified Canon 5D Mark II and infrared pass filters. The reflected IR imaging increased the contrast between some of the inks of the signatures and the wood. In some cases, the ink faded completely in the infrared indicating that different inks were used for signatures.

Infrared Reflectography (IRR) was carried out using a Xenics XC117B camera with an InGaAs sensor that has a spectral sensitivity of 900-1700nm. We did a visual investigation with the Xenics camera and acquired a few detailed images to see if the higher spectral sensitivity would aid in the identification of some of the signatures. Similar to the infrared imaging completed with the modified DSLR, the IRR increased the contrast between some of the inks and the wood and in some cases the ink faded completely in the infrared.

UV Image of Konter Ukulele

Reflected infrared digital image of the Konter Ukulele.

Ultraviolet-induced visible fluorescence was completed using a standard Canon 5D Mark II with Sirchie brand TigerUV lamps (mercury vapor, 150W power rating, 365nm bandpass filter). This technique did increase the visibility of some of the signatures, but these results were distracted by the fluorescence of a coating that may have been scrapped off creating on uneven urface in the uv-induced visible fluorescence images.

Reflectance Transformation Imaging (RTI) was done in both the full visible range and using a 660nm bandpass filter on the modified Canon 5D Mark II. The visible RTI was used to image the back of the ukulele, as there were noticeable signatures that had created an indentation. The grain of the wood and the close coloration of the wood and the ink make this RTI file difficult to interpret. We noticed that the 660nm bandpass filter produced images with a nice contrast between the ink and the wood, so we did captures for 660nm RTI of the front and the back of the ukulele.

VIS and FCIR Image of Konter Ukulele

Visible light image and False Color Infrared image of the Konter Ukulele.

Multispectral Imaging (MSI) was initially the acquisition of a visible image, an image with a 660nm bandpass filter and an image with an 880nm bandpass filter. This image set was acquired for the front, back and seven side views. Processing of these image sets included False Color Infrared (FCIR) and image subtraction. The FCIR images of the front and the back of the ukulele indicate the different inks used for the signature and has the potential of increasing the visibility of some of the harder to identify signatures. The image subtraction was the difference between the 880nm image and the 660nm image and is also aiding in the visualization of the signatures and the different inks.
A set of images was acquired of the front of the ukulele using the full kit of MidOpt bandpass filters (470nm, 525nm, 590nm, 635nm, 660nm, 695nm, 735nm, 800nm and 880nm). This set of images was processed using image subtraction, which may help with the identification of some of the signatures.

Conclusion
A variety of imaging techniques were used to document the signatures on the Konter Ukulele. The imaging has helped to identify a few additional signatures including the first two women to swim the English Channel. The images will continue to be further investigated by Larry Bartram and Dick Boak who are more familiar with the instrument, its history and the signatures previously identified.