  Spectral cameras with integrated thin-film Fabry-P\'erot filters have become
increasingly important in many applications. These applications often require
the detection of spectral features at specific wavelengths or to quantify small
variations in the spectrum. This can be challenging since thin-film filters are
sensitive to the angle of incidence of the light. In prior work we modeled and
corrected for the distribution of incident angles for an ideal finite aperture.
Many real lenses however experience vignetting. Therefore in this article we
generalize our model to the more common case of a vignetted aperture, which
changes the distribution of incident angles. We propose a practical method to
estimate the model parameters and correct undesired shifts in measured spectra.
This is experimentally validated for a lens mounted on a visible to
near-infrared spectral camera.
