lensrender op• Data kinds: table → table
• Call: import fullseye as fs; fs.ledger.render_ghost_overlay(system, scene=None, light_xy_mm=None, distance_mm=1000.0, intensity_W_sr_nm=1.0, reflectance=0.04, sensor=None, wavelengths=None, exposure_s=0.0001, rings=10, max_ghosts=6, defocus_mm=0.0, focus_mm=None, base_electrons=None, band_nm=None, illuminant=None) -> 'dict' (to call the implementation directly, import lensrender; lensrender.render_ghost_overlay(system, scene=None, light_xy_mm=None, distance_mm=1000.0, intensity_W_sr_nm=1.0, reflectance=0.04, sensor=None, wavelengths=None, exposure_s=0.0001, rings=10, max_ghosts=6, defocus_mm=0.0, focus_mm=None, base_electrons=None, band_nm=None, illuminant=None) -> 'dict'; from the registry, opsoptics.get("render_ghost_overlay"))
• GPU: none (CPU reference implementation only)
The two-reflection ghosts of a bright point, as electrons on the sensor -> dict.
The point is the scene's first source or, with *light_xy_mm* (x, y), a source at *distance_mm* in front of the lens with spectral intensity *intensity_W_sr_nm*. raytrace3d.ghost_analysis gives, for every pair of refracting surfaces, the ghost's energy relative to the image (R_i R_j times the transmittances along its path, *reflectance* being one value for all surfaces, or a raytrace3d coating spec) and the share of rays that reach the sensor; ghost_path gives the real rays of the strongest *max_ghosts* ghosts, which are spread over the pixels with the power I Omega T energy_ratio of the point. A reflectance of 0 gives an overlay that is exactly zero. The table has overlay_electrons (H, W), electrons_with_ghosts (when *base_electrons*, e.g. a render's electrons_mean, is given), image_electrons (the point's own image, for the ratio), ghosts (one row per ghost: surfaces i, j, energy_ratio, reach_fraction, power_ratio = their product, the footprint centroid in pixels (row, col) and its radius, and the offset from the main image in pixels), main_image_px and wavelengths_um. The point must be on or off the axis of an axisymmetric system; the sensor plane follows *defocus_mm* / *focus_mm* as in the render.
Every optics op validates its input before computing (nothing slips through silently):
• Units are baked into the argument name — _mm / _um / _deg / _mrad. Confusing mm with µm does not crash; it yields a plausible-looking wrong answer, so the name prevents it. Nothing here guesses the unit from the magnitude.
• Strings raise ValueError — float('50') succeeds, so an unparsed configuration value would slip through as a length (measured: thin_lens('50', '200') returned a plausible 66.667 mm). bool is refused too, as the implicit promotion True == 1.
• complex / masked arrays raise ValueError (real-valued slots only; silently dropping the imaginary part or peeling off the mask is refused). NaN/Inf raises ValueError on every input. Exception, declared: the u_map of bottle_fit_from_pattern takes pixels that could not be measured as NaN (infinity is still refused).
• Division by zero and its relatives are refused by name: focal length 0, radius of curvature 0, refractive index <= 0, a fully opaque aperture (all zeros, so the normalisation is 0/0), a PSF whose sum is <= 0, a Stokes vector with S0 = 0, and an object sitting at the front focal point (the image is at infinity).
• Only two ops return a non-finite value, and both state it as a contract: depth_of_field returns far_mm = inf beyond the hyperfocal distance (that is what the hyperfocal distance means), and gaussian_beam returns wavefront_radius_mm = inf at the waist (the radius of curvature of a plane wavefront). Both also return a finite companion (far_is_infinite / curvature_per_mm). Any other silent NaN/Inf is detected internally and raises ValueError — "float64 overflowed" and "the answer is infinite" are different claims, so the first is never returned wearing the face of the second. Exception, declared: bottle_background_map returns NaN in u_mm for pixels whose ray is unusable (total internal reflection and the like), together with a valid mask and the counts.
• Size caps: generated grids are capped by optics.MAX_GRID (4096); supplied fields/PSFs/apertures by optics.MAX_FIELD_ELEMENTS (2^24); ABCD element chains by optics.MAX_SYSTEM_ELEMENTS (1024); Zernike by MAX_ZERNIKE_TERMS (512) / MAX_ZERNIKE_ORDER (40) / MAX_ZERNIKE_BASIS (2^25). This closes, fail-closed, the paths where a small argument triggers a huge internal allocation (measured: n_max=40 × 4096² needs 108 GB).
• Physically impossible states are refused too: a Stokes vector with degree of polarisation > 1, negative transmittance, negative intensity, and invalid Zernike indices such as n-|m| odd.
• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).
• Operator provenance and references — the sources of the research/methods this op family came from.
• The canonical algorithm (author, year) and its uses are named in the family usage guide above.
• poc_photograph_through_prescription — py -3.11 examples/poc_photograph_through_prescription.py
table as input)abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd
lensrender)lens_scene · exit_pupil_samples · trace_sensor_rays · scene_radiance · render_scene_through_lens · bokeh_shape · render_compare_prescriptions
*Provenance: lensrender.py — OPTICS operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.