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.illumination_train(kind='kohler', source_mm=2.0, collector_f_mm=20.0, condenser_f_mm=10.0, field_stop_mm=6.0, aperture_stop_mm=6.0, source_distance_mm=30.0) (to call the implementation directly, import illumdesign; illumdesign.illumination_train(kind='kohler', source_mm=2.0, collector_f_mm=20.0, condenser_f_mm=10.0, field_stop_mm=6.0, aperture_stop_mm=6.0, source_distance_mm=30.0); from the registry, opsoptics.get("illumination_train"))
A microscope illumination train (kohler or critical) laid out paraxially (table).
Planes along the axis (thin lenses, distances in mm, z = 0 at the source):
• the source (a disc of diameter *source_mm*) at z = 0;
• the collector (focal length *collector_f_mm*) at z = *source_distance_mm*, with the field stop (diameter *field_stop_mm*) right at it; it images the source to z_A;
• the aperture stop (diameter *aperture_stop_mm*) at z_A, on the intermediate source image;
• the condenser (focal length *condenser_f_mm*):
• kohler: one focal length behind the aperture stop (the stop sits in its front focal plane, so the source is imaged to infinity), and the specimen where the condenser images the field stop;
• critical: two focal lengths behind the source image (a 1:1 relay), and the specimen where the condenser images the source. The aperture stop then sits at the source image (it trims the source), the field stop is in a pupil-like plane.
Returns the element list (elements: dicts with type lens / stop / source / specimen, z_mm, f_mm or radius_mm) that illumination_field traces, plus the conjugate bookkeeping read off the ABCD matrices: source_to_specimen and field_stop_to_specimen (A, B, C, D — B = 0 means "imaged onto the specimen"), source_magnification / field_stop_magnification (A when B = 0, else None), field_diameter_mm (the lit field: field stop x |M| for Koehler, source x |M| for critical), illumination_na (on-axis marginal ray: the smallest stop-limited angle), source_image_z_mm.
Raises ValueError: unknown kind, non-positive sizes or focal lengths, a source closer than the collector focal length (no real intermediate image), a specimen that would be virtual.
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_spectrometer_illumination — py -3.11 examples/poc_spectrometer_illumination.py
table as input)abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd
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.