Technical Photography and MSI calibration card
The TP-MSI Calibration Card brings together multiple reference standards in a single compact, robust, and lightweight tool, making it suitable for systematic documentation and examination of artworks using Technical Photography and Multispectral Imaging.
We offer the TP-MSI Calibration Card in two sizes: STANDARD and MEDIUM.
Table of Contents
Features
Our TP-MSI calibration card provides a simple and reliable way to incorporate reference standards into Technical Photography and Multispectral Imaging, while also supporting white balancing, exposure standardization, and lighting control.
The card is designed to be compact enough to fit directly into an art documentation setup, while remaining robust and lightweight.
The calibration card is a unique tool that complements the CHSOS Technical Photography and Multispectral Imaging kits and provides reference standards for a wide range of imaging techniques:
UV Fluorescence Photography (UVF)
The four standard swatches are used to check and standardize Ultraviolet Fluorescence Photography (UVF).
We selected four art materials as reference standards: shellac, madder lake, zinc white, and cadmium red.
These materials are mixed with an acrylic binder. The first three materials exhibit characteristic fluorescence under ultraviolet radiation:
– Shellac: bright orange
– Madder lake: orange-red
– Zinc white: pale yellow
Cadmium red, on the other hand, does not fluoresce. It is therefore used to check for light pollution or unwanted visible-light contamination affecting the UVF image.
Infrared Fluorescence Photography (IRF)
The cadmium red swatch is also used as a reference for this method, helping to check and standardize exposure.
Raking Light Photography (RAK)
The card features a gnomon to provide a reference for documenting the direction and angle of the illumination used during examination.
Polarized Light Photography
The gnomon also incorporates a rounded metal reflective surface that can be used to check polarized-light photography.
When the polarization system is correctly configured, the reflective top of the gnomon should appear dark, providing a simple visual check that the polarizing equipment has been properly set up.
Multispectral Imaging
The card contains six Multispectral Imaging (MSI) calibration swatches, providing standardized reflectance references to build the MSI cube. The grey swatches also serve as white balance references.
Spectral images can be reflectance-calibrated using the TP-MSI Calibration Card as an in-scene reflectance standard. Its white, black, and four grey patches provide reference values for image calibration. Their respective reflectance values are 100%, 80%, 60%, 40%, 20%, and 5%.
Scale
A 20 mm scale provides a convenient reference for quick dimensional measurements.
TP-MSI CARD - STANDARD
The STANDARD version (78×18 mm) is included with the Pigments Checker and is also available for purchase separately.
The Standard card features a magnetic support designed to attach directly to the Pigments Checker. This allows you to practise taking Technical Photography (TP) and Multispectral Imaging (MSI) images with the Pigments Checker and use the calibration card for accurate image correction and processing. Although primarily intended for practice and use with the Pigments Checker, its dimensions are still suitable for the calibration of images of typical easel paintings.
TP-MSI card - MEDIUM
The MEDIUM version (122×36 mm) features larger 18 × 18 mm reference targets, making the individual targets easier to identify and sample when working with greater shooting distances or large objects.
