As discussed, a physically based camera, with chromatic aberration (longitudinal and transversal), and modelling other phenomena as well (vignetting, coma, astigmatism), and rolling shutter.
Lens flare could also be added, and presets for these phenomena to match real world lenses. Since there are databases of lenses to correct these distortions with camera images, it would be possible to do the opposite and take this data to apply the distortions, instead of correcting them.
As discussed, a physically based camera, with chromatic aberration (longitudinal and transversal), and modelling other phenomena as well (vignetting, coma, astigmatism), and rolling shutter. Lens flare could also be added, and presets for these phenomena to match real world lenses. Since there are databases of lenses to correct these distortions with camera images, it would be possible to do the opposite and take this data to apply the distortions, instead of correcting them.