illumination op• Data kinds: table → image2d
• Call: import fullseye as fs; fs.ledger.illumination_field(train, source_radiance=None, shape=(65, 65), field_mm=None, n_pupil=16) (to call the implementation directly, import illumdesign; illumdesign.illumination_field(train, source_radiance=None, shape=(65, 65), field_mm=None, n_pupil=16); from the registry, opsoptics.get("illumination_field"))
Irradiance on the specimen of an illumination train (image2d), by paraxial backward tracing.
For every specimen pixel (x, y) and every direction (u, v) on an *n_pupil* x *n_pupil* grid of the illumination cone, the ray is traced back through each stop (rays outside a stop are blocked) to the source plane, where the radiance is looked up: E(x) = sum L(source point) du dv (paraxial, so for a uniform source filling the cone E = L pi NA^2 — a gate).
*train*: the table from illumination_train (or the same element list built by hand). *source_radiance*: None = uniform radiance 1 over the source disc; or a 2-D array of non-negative radiance laid over the square [-r, r]^2 of the source (r = source radius), bilinear lookup, zero outside the disc — a filament, an LED die, a fibre bundle. *shape*: the output grid (rows, cols). *field_mm*: half-width of the square specimen window (None = 0.65 x the lit field diameter). *n_pupil*: direction samples per axis.
Returns the irradiance map (float64, rows = +y down to -y as an image), in radiance x sr units.
Raises ValueError: not a train, non-finite/negative radiance map, work above MAX_TRAIN_WORK, no light reaching the specimen.
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.
• 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.
• 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.
• mv_illumination_practice — Lighting in practice — wavelength, polarisation, drive modes, ambient light, safety
• 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_document_scan — py -3.11 examples/poc_document_scan.py
• poc_spectrometer_illumination — py -3.11 examples/poc_spectrometer_illumination.py
image2d as input)fraunhofer_pattern · pupil_psf · pupil_blur · psf_to_mtf · encircled_energy · ensquared_energy · energy_radii · mtf_tangential_sagittal
illumination)light_source · irradiance_map · illumination_uniformity · defect_contrast · lighting_sweep · illumination_design · solid_angle_light · solid_angle_boundaries
*Provenance: illumdesign.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.