INFO
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To determine dichotomous UVR and NIR responses, please refer to the L* value of your sample from the CIELAB color space.
DARK: L* ≤ 80
BRIGHT: L* ≥ 81
If reference value: X-rite Color Checker Classic A4: L*=96
To determine UVF response, please use the MUNSELL calculator to convert Lab values to Munsell Hue and Chroma.
*The system does not provide quantitative fluorescence intensity in physical units (e.g., radiance or lumens). If precise fluorescence intensity measurements are required, consider using spectrophotometers, fluorometers, or imaging systems with calibrated fluorescence intensity scales. These tools can provide absolute values rather than relying on visual assessments.
Munsell color notation: HUE, VALUE/CHROMA
FLUORESCENCE: CHROMA > 20
[If less than 20, UVF: NONE]
UVF HUE: R, YR, Y, GY, G, BG, B, PB, P, and RP
[Hue has been divided into the 10 Munsell hue sectors, Red, Yellow-Red etc.]
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To calculate a response vector graph, please use the VECTOR CHART calculator to chart Lab values measured from each wavelength band.
*The calculator only provides discrete, approximate values. For more accurate and continuous values, please use a spectrophotometer.
Vector response chart for Cochineal ︎
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Imaging set - up:
Camera: Modified Canon 5DSR infrared conversion.
Lens: Coastal Optics Apochromatic lens, 60mm, 1:4.
Filters: VIS - IDAS-UIBAR III [400-680nm], UVR - XNite 330C + XNite BP1 [270-400nm], UVF - IDAS-UIBAR III + Wratten 2E [420-680nm], IR - XNite 830 [830-1100nm].
Lights: LED bulbs, standard copy set-up using lights designed by the Metropolitan Museum of Art: These 24” linear fixtures were designed to provide consistent uniform illumination for technical cultural heritage imaging. D50 98CRI ISO 3664 compliant visible white channel, 365nm UV, and 950nm IR. The unique compact form-factor incorporates a rotating body to maintain consistent lighting geometry for critical comparative study and multi-band imaging techniques.
Targets: x-rite classic mini color checker, UV innovations target [low/medium], labsphere spectralon 5% + 99%.
Backgound paper: Color-aid Gray 4 (non-fluorescing neutral gray).
Questions: lauramargaret.ramsey(at)metmuseum.org
*IDAS-UIBAR III no longer available.
Comparable options, in order of performance1
VIS: MidOpt BP550 [390-740], UVF: MidOpt BP550 + Wratten 2E [420-740]
VIS: MidOpt SP700 [400-780], UVF: MidOpt SP700 + Wratten 2E [420-780]
VIS: PECA 918 [380-740], UVF: MidOpt SP700 + Wratten 2E [420-740]
1. Mastandrea, W.J., K. McFarlin, C. Heins, A. Grant, R. Greenberg, A. Serotta, and D. Kriss. “The 12th International Round Table on Polychromy in Ancient Sculpture and Architecture.” In Letting the Light In: A Comparative Assessment of Visible Bandpass Filters Used in Multiband Imaging of Material Culture. Los Angeles, 2024.
DRPR-2010_232-20250424-AT-Recto-VIS
Imaging
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