Direct answer
A photometric report is a calculation produced by lighting software from a stated layout, stated fixture data, and stated assumptions. Verify it by checking that the grid spacing and extent are stated, the light-loss factor and its components are stated, the fixture data matches the model being supplied, the mounting heights and aiming are documented per pole, and the results are labelled as calculated. A photometric report is not a certification and no software issues one.
Who this is for
Owners' representatives, consulting engineers, architects, athletic directors, and purchasing staff who receive a photometric report as part of a submittal and need to know whether it can be relied on and what it does not cover.
What a photometric report is
Lighting design software takes a geometric model of the site, the locations and aiming of each luminaire, a photometric data file describing how each luminaire distributes light, and a set of depreciation assumptions. It returns predicted illuminance at each point on a defined grid, together with derived statistics such as average, minimum, maximum, and uniformity ratios.
Every one of those outputs is Calculated. The calculation is only as good as its inputs, and its inputs are all stated on the report — which is exactly why the report is verifiable.
AGi32 and comparable packages are design tools. They compute results. They do not certify, approve, or warrant anything, and a report bearing a software name is not an endorsement by that software's publisher.
Inputs required before a report can be verified
1.The luminaire schedule, with manufacturer, model, and quantity as they will be supplied.
2.The photometric data file used for each luminaire type, traceable to a published test report.
3.The site model: surface dimensions, pole locations, mounting heights.
4.The aiming data, by fixture and by pole.
5.The calculation grid: spacing, extent, and height above the surface.
6.The light-loss factor and its components.
7.The illuminance target and the standard it comes from.
If any of these is absent, the report cannot be independently checked, and an unverifiable report should not be accepted as a submittal deliverable.
The verification points, in order
One — does the fixture data match the fixture being sold? The photometric file must correspond to the exact model, wattage, optic, and colour temperature quoted. A report run on a higher-output variant than the one being supplied will overstate results. Ask for the underlying test report and check the model designation letter for letter.
Two — is the grid stated, and is it appropriate? Grid spacing determines how many points are sampled. A coarse grid can miss dark spots between poles and can flatter uniformity ratios. Check spacing, check that the grid covers the area the standard requires, and check the calculation height above the surface.
Three — is the light-loss factor stated with its components? A single LLF number without components is not verifiable. Ask which depreciation factors were included, what maintenance interval was assumed, and whether the LLF reflects the actual cleaning and relamping regime the owner will fund. An optimistic LLF produces a report that looks better and a facility that performs worse.
Four — are the results labelled maintained or initial? Maintained values include the light-loss factor. Initial values do not. Comparing an initial average against a maintained target is a category error that makes a design look compliant when it is not.
Five — is aiming documented per fixture and per pole? Without aiming data the report cannot be reproduced and the installation cannot be commissioned against it. Aiming is also the single most common source of divergence between calculated and field results.
Six — are spill and glare treated at named points? Check that any statement about light beyond the playing surface refers to specific, named evaluation points with stated locations, and that the values are labelled as calculated. Treat any absolute promise about spill or glare as a claim that cannot be supported by a calculation.
Seven — is vertical illuminance addressed where the application requires it? For broadcast, video review, or certain levels of play, horizontal illuminance alone is insufficient. Confirm which planes were calculated.
Eight — is the report signed, dated, and attributed? A report with no author, no date, and no revision number cannot be tied to a submittal cycle.
What gets evaluated, and how each figure is labelled
Figure | Label | Meaning |
Average maintained illuminance | Calculated | Software output for the stated layout and LLF. |
Minimum and maximum illuminance | Calculated | Software output at grid points; sensitive to grid spacing. |
Uniformity ratios | Calculated | Derived from the same grid points. |
Vertical illuminance at stated planes | Calculated | Only present if requested and modelled. |
Illuminance at named spill points | Calculated | Depends entirely on which points were chosen. |
Luminaire lumen output and distribution | Reported | From a laboratory photometric test report on a specific sample. |
Colour temperature and colour rendering | Reported | From the same test report or the manufacturer's published data. |
Lumen maintenance projection | Reported | Derived from LM-80 data via TM-21; a projection. |
Certification status | Listed | A directory record, verifiable by file number. |
Post-installation illuminance | Field-measured | Produced after installation with a stated meter and procedure. |
Retrofit versus new construction
On new construction the report models an idealised site: poles exactly where drawn, at the height drawn, with no obstructions. Divergence in the field comes mainly from construction tolerance and aiming.
On a retrofit the report models a site that already exists, with pole positions and heights that were set for a different fixture and possibly a different sport. Verify that the pole locations and heights in the model were surveyed rather than assumed, and that any obstructions — trees, structures, adjacent fencing, existing signage — were included or explicitly excluded. A retrofit report built on assumed geometry is a design sketch, not a verification.
What can change the answer
•A change of fixture model, optic, or colour temperature invalidates the report.
•A change in pole location or mounting height invalidates the report.
•A revised maintenance interval changes the defensible LLF and therefore every maintained figure.
•Adding a requirement for vertical illuminance or for broadcast-level play changes the design basis.
•A different adopted edition of the governing standard changes the targets the report is checked against.
•Field aiming that differs from the aiming report changes real results without changing the report.
Verification checklist
1.Luminaire schedule matches the products quoted, model for model.
2.Photometric data file is traceable to a published test report for that model.
3.Grid spacing, extent, and calculation height are stated.
4.Light-loss factor is stated with its components and the maintenance interval assumed.
5.Results are labelled maintained or initial, unambiguously.
6.Mounting heights and pole coordinates are stated and, on retrofits, surveyed.
7.Aiming is documented by fixture and by pole.
8.Spill values, if present, refer to named points with stated locations.
9.Vertical illuminance is included where the application requires it.
10.Every reported figure carries its label; no figure is described as measured.
11.The report is signed, dated, and revision-controlled.
12.No language in or around the report describes it as certified, approved, or guaranteed.
Duvon's role and limits
Duvon Lighting prepares calculated photometric layouts for our own products and supplies the photometric data files and product documentation an independent designer needs. We state grid, light-loss factor, mounting heights, and aiming on every layout we issue, and we label results as calculated.
We do not certify photometric results, and no lighting software certifies them either. We do not perform the engineer of record's design review. Where a project requires an independent photometric design or a stamped submittal, that work belongs to a licensed professional engaged by the owner.
Next step
Send us the surface dimensions, pole positions and heights, sport and level of play, and the target you are designing to. We will return a calculated layout for our products with the grid, light-loss factor, and aiming stated on the face of the report.