. "http://eilv.cie.co.at/term/798"^^ . . . . . "Napierian Absorbance"@en . "Napierian Absorbance is the natural (Napierian) logarithm of the reciprocal of the spectral internal transmittance." . "\\(A_e(\\lambda) = -ln(\\tau(\\lambda))\\), where \\(\\tau\\) is the transmittance at a given wavelength \\(\\lambda\\)."^^ . "A_e, B" .