Effect of continuum slope on spectral adsorption minimum

Plot of reflectance versus wavelength showing the effect of continuum slope on adsorption minimum as applied to spectral data.  Continuaa can be thought of as an additive effect of optical constants, but in reflectance spectra, scattering and Beers Law make the effects non-linearly multiplicative. So the continuum should be removed by division, whether you are working in reflectance or emittance. The continuum should be removed by subtraction only when working with absorption coefficients. In a spectrum with a sloping continuum, correction removes the effect of shifts in the local reflectance minimum.