AIC's 52nd Annual Meeting

In 2022, an assessment focusing on measuring the acidic off-gassing of The Mariners’ Museum and Park’s motion picture film collection was completed. This assessment employed A-D Strips®, colorimetric and photographic documentation, and creation of a set of reference strip standards exposed to known concentrations of acetic acid. A-D Strips are a proven method of evaluating acetic acid off-gassing from cellulose acetate film. A previous study conducted by the authors sought to standardize the interpretation of the color changes made to the strips by exposure to acetic acid.

Photographic images were collected under both standard studio conditions and working survey conditions in the 2022 investigation. In 2023, RGB values were collected from these images of strips and compared to the L*a*b* colorimetric values. These RGB values and L*a*b* colorimetric measurements are compared in this study with the goal of assessing how differences in photographic conditions impact interpretation of the results. This investigation examines the feasibility of standardizing photographic interpretation of A-D Strips using RGB values of photographs collected under varying lighting conditions. Success of this standardization could possibly circumvent the need for a colorimeter. Finally, a set of standardized RGB values for printing a calibrated scale is proposed.