Spectral tools - Whiteness
|
|
|
|
This tool set is designed to rapidly measure white paper characteristics: Whiteness, Tint, Brightness, Fluorescence, and Opacity. The fluorescence is obtained by the difference of the measured brightness without and with a UV-blocking filter (Fluorescence = 99,8 - 89,8 = 10,0 in the above screenshot). The opacity is obtained by ratio of the paper luminance (the Y of XYZ) measured on the black backing on the luminance measured on the white backing. The paper used for the above measurements displays a strong fluorescence typical of "Bright White" papers sold for office reports, and which is acceptable for such a use; however, this is not the best paper for high-quality photographic printing if you are looking for a time-stable print that can be viewed in different illumination settings containing various amounts of UV light (i.e. halogen lights indoor vs daylight). Because a measurement made with the non-UV-cut Eye-One plus a separate UV-cut filter is equivalent to making measurements with an Eye-One fitted with a permanent UV-cut filter, you can use the Whiteness tools to rapidly make measurements with and without UV-cut. Such measurements can also be done on colored patches, and are thus not limited to white paper, although you should only look at the L*a*b* values in this case, and disregard the Whiteness, Brightness, etc. values. For measurements without a UV-cut filter, you have to use the "Paper on Wh" button, and for UV-cut measurements you need to place the UV filter between the Eye-One and the color patch, and press the "Paper w/filter" button. Important: Fluorescence measurements require a thin, transparent, UV filter, which is not provided, and an Eye-One which is NOT UV-Cut. The other measurements require compliant white or black backings, which are also not provided; however, you can easily check white and black backings compliance with the provided tools. You can also characterize any equivalent UV filter you may have and use it in this tool (please consult the Help manual for the procedure). The screenshot below shows the image obtained with the "Save image..." button for a 2X print scale; this image can also be generated at a 1X scale.
|
|
