Turbidity Effect in Spectrum Line Photometry

Abstract

Owing to the turbidity of the undeveloped emulsion, the characteristic curve (the H and D curve) of an emulsion has a different slope when densities from the negative image of a point or line source instead of densities from the negative image of an extended source are used to construct it. As a result, line and background intensities are not additive in their effect upon the emulsion, and background corrections based upon the assumption that line and background densities may be referred to a common characteristic curve lead to erroneous results. The effect was discovered experimentally by Slavin, and independently, by Shipitsyn The magnitude of the effect is dependent upon emulsion parameters and wavelength. Its direct observation may be influenced by the presence of the Eberhard effect which tends to change the relative slopes of point and extended image characteristic curves m a direction opposite to that of the turbidity effect