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We discuss the true definitions of specular and diffuse reflection. Many people think that diffuse reflection is Lambertian reflection. Such is not the case. Lambertian is a special type of diffuse reflection, and the often-used equations for Lambertian reflection cannot, in general, be used in display-reflection considerations.
Kelley, E.
(2008),
Diffusion Confusion, Journal of the Society for Information Display, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=32864
(Accessed October 27, 2025)