Abstract
Although the spectral reflection curves of white diffusing paints used for inner coating of a photometric sphere are desired to be flat in visible region, the curves are markedly influenced by thicknesses of the coating layers. The color inside the illuminated sphere changes from a bluish cast through white to ivory as the thickness increased. Therefore, there must be the most suitable thickness for each paint.
For smoked MgO coating and other white coatings in the sphere, the auther measured the spectral reflecting distributions of them relating to their coating thicknessed and aiscussed the color temperature changes of the light from the photometric sphere.
