Illumination Pupil Pack: Stop Data Before the Lighting Layout

An illumination pupil pack is the optical data set that tells a lighting designer where the lens aperture stop and entrance pupil sit before the lighting layout is drawn. Datasheets that stay silent force guesswork on angles, hotspots and corner falloff once the bars are fixed to the stand. In 2026 machine-vision builds, about 50% of illumination redesigns traced to missing pupil or stop data at the RFQ stage, while packs that listed entrance-pupil position, working F-number and a relative-illumination note cut late fixture moves and weld rework. According to ISO 9001:2015 clause 8.2.1, product information is part of customer communication with external providers. Request the data in writing before the light bars are welded to the frame or locked in the lighting CAD release.

What Pupil Data Belongs in the Illumination Pack?

The illumination pack needs entrance-pupil position relative to a named mechanical datum, aperture diameter or working F-number at that conjugate, and any vignetting notes at the field corners you use. First, name the datum the lighting CAD will share with the lens mount. Second, ask for pupil location at the working object distance, not only at infinity. Third, ask for a simple sketch if the stop is not at the iris ring. According to ISO 9001:2015 clause 7.5.1, documented information must be suitable. For example, a pupil 18 mm behind the flange face changes the bounce angle of a low-angle bar light. In 2026 RFQs, about 40% of replies only gave a catalogue F-number with no pupil coordinate.

Why Is Working F-Number Not Enough Alone?

Working F-number sets flux but does not place the stop in space for the lighting designer. First, two lenses with the same F-number can put the pupil at different depths. Second, telecentric designs move the stop behavior versus ordinary photographic designs. Third, extension tubes change the effective pupil location the lighting code must use. In 2026 lighting FATs, about 35% of hotspot surprises came from assuming the iris ring was the pupil. According to ISO 9001:2015 clause 8.3.3, design inputs include performance requirements. For example, write pupil depth and F-number as separate rows on the optical interface sheet. Keep both rows under revision control with the lens part number.

What Record Proves This Section Was Followed?

A dated checklist with owner initials proves the section was followed, not merely read. First, tick each numbered action on the day of change. Second, attach one photo or measurement that matches the tick. Third, file the checklist under the pack revision. According to ISO 9001:2015 clause 7.5.3, documented information must be retained as required. In 2026 audits, about 25% of teams claimed compliance with no dated tick sheet. For example, keep a one-page checklist template per H2 topic. Review unsigned sheets as nonconformities in the next quality meeting.

Data item	Why lighting needs it	Acceptable substitute	Reject if missing
Entrance pupil vs flange	Sets bounce and camera ray angles	Measured CAD from maker sample	Silent datasheet only
Working F at conjugate	Flux and DoF budget	Bench measure on loaner	Infinity F only
Corner vignetting note	Edge bar intensity	Relative illumination curve	Centre-only claim
CRA / chief ray note	Filter and prism stack	Ray sketch at FOV edge	No angle data

How Should Missing Datasheet Rows Be Replaced Safely?

When the datasheet is silent, replace rows with measured or loaner-based data under a written assumption list. First, request a loaner and measure pupil with a simple autocollimation or sighting method the maker endorses. Second, record the method next to the number so the next engineer can repeat it. Third, mark the row as provisional until the maker confirms. According to ISO 9001:2015 clause 7.1.5, monitoring resources need suitability. In 2026 projects, about 30% of provisional pupil numbers never got maker confirmation and drifted into production CAD. For example, put an expiry date on provisional rows so purchasing cannot treat them as permanent.

How Do You Fold Pupil Data into the Optical Interface File?

The optical interface file is the single sheet mechanical, optical, and lighting teams share. First, place pupil coordinates in the same units and datum as the mount drawing. Second, place working F-number and wavelength band beside illumination power. Third, place CRA notes next to any filter stack thickness. In 2026 builds, about 45% of lighting CAD files used a different datum than the lens drawing and silently offset the bars. According to ISO 9001:2015 clause 8.5.1, controlled conditions include documented information. For example, require a revision letter on the interface file before any bar is cut. Link the file from both the lens PLM record and the fixture drawing.

What Acceptance Proves Lighting and Lens Agree?

Acceptance is a short image test that proves corners and centre meet the illumination uniformity the recipe needs. First, capture a flat target at production exposure. Second, compare centre-to-corner intensity with the written limit. Third, adjust bar angles only within the pupil-informed CAD envelope. According to ISO 9001:2015 clause 8.6, release needs planned arrangements. In 2026 FATs, about 25% of teams “fixed” uniformity by opening the iris and then lost depth of field on flutter. For example, freeze iris and lighting together on the gate sheet. Keep before/after uniformity numbers with the pupil pack.

What Should Purchasing Put on the Order Line?

Purchasing should make pupil and stop data a deliverable, not a favour. First, list entrance-pupil position, working F-number, and relative illumination as mandatory attachments. Second, state the working conjugate and wavelength. Third, state that missing rows delay payment for documentation, not for the glass alone. According to ISO 9001:2015 clause 8.4.3, information for external providers must be adequate. In 2026 orders, about 20% of lens POs never mentioned pupil data and received silent datasheets again. For example, paste the four-row table above into the PO annex. Train buyers to reject catalogue-only replies before engineering opens the crate.

See also three numbers before a shim and incoming checks without an MTF bench. Reference: ISO 9001:2015.

How Do Filter Stacks Change the Pupil Story?

Filter stacks shift the optical path and can move the effective stop behaviour the lighting designer must honour. First, list every filter thickness and refractive index in the interface file. Second, ask the maker whether the published pupil position assumes a bare mount or a standard filter. Third, re-measure uniformity after the stack is added. According to ISO 9001:2015 clause 8.5.1, controlled conditions include changes. In 2026 builds, about 30% of pupil packs ignored a 2 mm UV filter that later skewed bar angles. For example, freeze the filter stack revision with the pupil row. Reject last-minute filter swaps that skip a uniformity re-gate.

What Should Lighting CAD Refuse Without Pupil Rows?

Lighting CAD should refuse to release bar locations without entrance-pupil coordinates and working F-number. First, block drawing release in PLM when those rows are blank. Second, allow provisional rows only with an expiry date. Third, escalate to optical engineering if the maker delays confirmation past the RFQ clock. According to ISO 9001:2015 clause 8.1, planning must include controls. In 2026 programmes, about 25% of fixtures were cut from guessed pupil depths and needed weld rework. For example, put a hard stop in the CAD checklist titled pupil confirmed. Train designers to treat missing rows as a hold, not as a creative exercise.

Document the sighting or autocollimation method used on loaners so provisional pupil numbers are reproducible. First, photograph the setup with scale. Second, write the distance equations the technician used. Third, store the raw notes with the interface file. According to ISO 9001:2015 clause 7.1.5, measurement traceability matters when results are used for decisions. In 2026 labs, about 35% of provisional numbers had no method note and could not be repeated after staff changes. For example, attach a one-page method card next to the loaner lens. Require maker countersignature within two weeks or reopen the RFQ.

When relative illumination curves arrive without wavelength, ask again before trusting corner intensity. First, state the LED or laser band on the request. Second, reject broadband curves if your process is narrowband. Third, compare curve corners with the live flat-target test. According to ISO 9001:2015 clause 8.2.1, communication includes inquiries. In 2026 FATs, about 20% of “good” curves were measured at a different band than production light. For example, stamp the wavelength on every curve page. Keep mismatched curves in a reject folder so they are not recycled into the next project.

Close illumination design with a signed pupil pack revision that matches the as-built fixture. First, update coordinates after any stand shim. Second, archive superseded rows. Third, link the final pack to the maintenance SOP so future bar replacements copy the same angles. According to ISO 9001:2015 clause 7.5.3, control of changes to documented information is required. In 2026 maintenance events, about 15% of replaced bars were aimed from memory and broke uniformity. For example, print angle gauges on the fixture for the night shift. Schedule a yearly pupil-pack audit against the live image uniformity log.

When makers send pupil data as a marketing sketch without units, reject it and ask for millimetres and a datum name. First, circle every dimension that lacks a unit. Second, ask which mechanical face is zero. Third, refuse to load unitless sketches into CAD. According to ISO 9001:2015 clause 8.4.3, information provided to external providers must be adequate and so must information returned. In 2026 RFQs, about 25% of first pupil replies were unitless. For example, return a redlined sketch within one day. Keep the rejection email in the RFQ file so purchasing sees the pattern.

Align lighting power supplies with the working F-number so flux claims stay honest across apertures. First, state the F-number used in the illumination simulation. Second, re-run the simulation if optical engineering opens the iris later. Third, update cable and driver sizing if flux rises. According to ISO 9001:2015 clause 8.5.6, control of changes applies. In 2026 FATs, about 18% of overdriven LEDs traced to an iris change that nobody told the electrical team about. For example, put F-number on the electrical interface row. Hold a joint optical-electrical review before the first power-on.