Relation between Object Position and Autocorrelation Spots in the Vander Lugt Filtering Process. 2: Influence of the...

It is well known that the optical Fourier spectrum of an object does not depend on its position in the object space. One generally concludes that the correlation with a Vander-Lugt filter is likewise invariant with respect to object position. The present investigation shows that the correlation signal is not object position independent, at least, when the filter is recorded on a recording material of nonvanishing thickness. For a conventional photographic emulsion, we show that the correlation signal depends very strongly on object position.