Radial profiles of the point-spread function (PSF) for FORCAST/SOFIA at 34.8 μm obtained with the Ceres and stellar calibrators. The theoretical PSF profile (blue solid line) computed by our custom IDL code is also shown for comparison. The vertical dashed and dot-dashed lines mark the FWHM of the stellar and Ceres PSFs, respectively. Our hybrid PSF is a combination of the stellar calibrators (for the region inside 10″) and the theoretical PSF (for the region outside 10″; for details see Section 3.1).