Nachweisgrenze schwacher Ramanlinien auf Photoplatten. II. Spektraldichte und Varianz von «Kornnoise» allein

The autocorrelation function of photographic granularity has been assumed to be described by an isotropic function R N ( x ) = R 0 (sin(π x / x 0 ))/(π x / x 0 ), cf. (2–3). Formulas for the distortion of the corresponding power spectrum due to the effect of slit function (rectangular slit 21·2 ϱ s) and of recording by a simple RC network (transfer function (1 + iωτ) 1 , time constant τ, scanning speed v 1 , recording speed v 2 ) have been derived. The results are expressed as the ratio defined by the variance of noise after passing the photometer divided by the variance without distortion by the photometer, 2 σ′/σN. The discussion of numerical application shows that there exists a certain region – slit variable x < 0,5, recording parameter p ≥ 0,5–1,0–, where this ratio cannot be influenced by increasing μ.