Subject: Near infrared spectra
Mark Clarke <markey [at] gn__apc__org> writes >Does anyone have (or have references to) Near IR spectra of >pigments? > >The region I am interested in is 700-900 nanometers, and the >materials I am most urgently interested in are Lapis Lazuli, Indigo, >Azurite and Smalt. My English is not enough to write. **** Moderator's comments: The following is a translation. Apologies for any inaccuracy You could find responses to the questions in one of the following, notably in the first one: Walmsley, Elizabeth, Colin Fletcher, and John Delaney. Evaluation of system performance of near-infrared imaging devices. Studies in conservation Volume 37, Number 2, 1992 pp. 120-131 Walmsley, Elizabeth, Catherine Metzger, Colin Fletcher, and John K. Delaney. Evaluation of platinum silicide cameras for use in infrared reflectography. Preprints. ICOM Committee for Conservation tenth triennial meeting, Washington, DC, 22-27 August 1993 Delaney, John K., Catherine Metzgar, Elizabeth Walmsley and Colin Fletcher. Examination of the visibility of underdrawing lines as a function of wavelength. Preprints. ICOM Committee for Conservation tenth triennial meeting, Washington, DC, 22-27 August 1993: preprints Personally, I use a CCD Camera (700-1100 nm) and supplement it with a Hamamatsu vidicon (1800-2200 nm). In practice, they complement each other and sometimes they appear to contradict the theory expressed in these articles. I mean, I observed in doing "homework" with either one or the other, these supposed elements ar not visible in the respective wavelengths of each camera. But all that enhances an empiric course not yet formalized. Gerard de Wallens Laboratoire de Recherche et d'Analyse Scientifiques de Tableaux. 52 Elysee II 78170 La Celle Saint-Cloud +33 1 39 69 60 80 Fax: +33 1 39 69 60 86 *** Conservation DistList Instance 13:48 Distributed: Friday, March 24, 2000 Message Id: cdl-13-48-004 ***Received on Wednesday, 1 March, 2000