solid_angle_light — OPTICS illumination op

• Data kinds: none → table (an op determined by its arguments alone — it takes no image or data input)

• Call: import fullseye as fs; fs.ledger.solid_angle_light(half_angle_deg=10.0, tilt_deg=0.0, azimuth_deg=0.0, radiance=1.0, distance_mm=100.0, n=64) (to call the implementation directly, import illumdesign; illumdesign.solid_angle_light(half_angle_deg=10.0, tilt_deg=0.0, azimuth_deg=0.0, radiance=1.0, distance_mm=100.0, n=64); from the registry, opsoptics.get("solid_angle_light"))

Usage

A light defined by the cone of directions it delivers to every point (table).

Every point of the part receives light from the same cone: axis tilted *tilt_deg* from the camera axis (+z) toward *azimuth_deg*, half-angle *half_angle_deg* (the illumination NA is sin of it), uniform *radiance* inside it. This is the far-field (Koehler) limit that an illuminator with a lens in front of the emitter approximates; a coaxial light through a half mirror is the case tilt_deg = 0. The record solid_angle carries the cone for solid_angle_brightness, solid_angle_boundaries, solid_angle_sweep and solid_angle_render; the dict also holds *n* emitters on a disc at *distance_mm* that subtends the same cone at the origin, so irradiance_map and defect_contrast accept it as well (they then see a near-field disc, not the far-field cone).

Returns the light dict (kind = "solid_angle") with solid_angle = {half_angle_deg, tilt_deg, azimuth_deg, radiance, axis, solid_angle_sr, projected_solid_angle_sr}; solid_angle_sr = 2π(1 − cos α) and the projected solid angle π sin²α is the irradiance a surface facing the cone receives per unit radiance. Fails closed (ValueError) when the cone would reach below the part plane (half_angle + tilt > 90).

Family-wide input contract (fail-closed)

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.

Detailed usage guide

• optics_imaging family guide

Background guides (the physics and conventions behind this op)

• mv_illumination_practice — Lighting in practice — wavelength, polarisation, drive modes, ambient light, safety

References (sample data, literature)

• 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.

Runnable examples (verified samples that actually call this op)

• poc_illumination_cone_vs_na — py -3.11 examples/poc_illumination_cone_vs_na.py

Ops the type connects to (they accept table as input)

abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd

Same category (illumination)

light_source · irradiance_map · illumination_uniformity · defect_contrast · lighting_sweep · illumination_design · solid_angle_boundaries · solid_angle_brightness


*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.