Detection and/or filtering of optical scenes by analog techniques usually requires separate filters for amplitude and phase. The Vander Lugt (holographic) filter provides the phase correction and the same filter can provide some amplitude correction if the nonlinearity of the film processing is used judiciously. This study shows how the control parameters, namely, exposure time and reference beam-to-signal ratio, can be chosen to modify the amplitude of the effective filter. The distortion is characterized in terms of a transfer curve which maps the input filter into the effective filter. Some experimental results are presented to demonstrate the theory.