IES file viewer
Drop any IES file here, ours or someone else's. The browser draws the light distribution curve, computes the flux from the curve itself, compares it with the flux stated in the file and shows what the luminaire delivers on the floor. Nothing is uploaded: the whole analysis runs on your device.
IES file
File A
Drop a file into this area, pick one from disk or paste the file text. Formats: IES (every LM-63 edition) and LDT (EULUMDAT).
Paste the file text
Worth knowing about this file
File B
Drop a file into this area, pick one from disk or paste the file text. Formats: IES (every LM-63 edition) and LDT (EULUMDAT).
Paste the file text
Worth knowing about this file
What is in the file
| File A | File B | |
|---|---|---|
| Luminaire | - | - |
| Manufacturer | - | - |
| Format | - | - |
| Test report and date | - | - |
| Light source | - | - |
| Flux stated in the file | - | - |
| Flux computed from the curve | - | - |
| Difference | - | - |
| Power | - | - |
| Efficacy from the file | - | - |
| Peak intensity | - | - |
| Direction of the peak | - | - |
| Beam angle at 50%, C0 / C90 | - | - |
| Field angle at 10%, C0 / C90 | - | - |
| Distribution class to GOST R 54350 | - | - |
| Share of flux to the lower hemisphere | - | - |
| Upward spill (IES cutoff) | - | - |
| Symmetry | - | - |
| Planes and angles | - | - |
| Luminous opening, m | - | - |
| Colour temperature | - | - |
Intensity by angle
Heat map of the table in the file: azimuth C across, angle from nadir down. The denser the colour, the more candelas.
Isolux plot on the floor
Illuminance from one luminaire on a horizontal plane: E = I(C, γ) · cos³γ / h² / Kz. Grid in metres, labels in lux. Direct component only, no reflections.
Photometric solid
The same table in three dimensions: the distance from the centre to the surface is proportional to the intensity in that direction. Rotate it to see the asymmetry between planes.
Room illuminance estimate
How many lux this luminaire gives in a rectangular room. Only the direct component is computed: light that arrives straight from the luminaire, with no reflections from walls or ceiling and no maintenance factor.
- Average illuminance
- -
- Minimum
- -
- Maximum
- -
- Uniformity, Emin/Eavg
- -
- Luminaires in total
- -
Illuminance map, lx
This is an estimate, not a design. Reflections add light; dust and depreciation take it away. The exact calculation to ShNK 2.01.05-24 is done by an engineer in DIALux from your floor plan, and it is free.
Opens the calculation form with the file name in the message. Attach the file itself to the form: it does not leave this page.
Why this is here
The photometric file is the one document a lighting designer uses to calculate your site. It carries two numbers for flux: the one written in the header and the one its own curve produces. When they disagree, the DIALux calculation comes out wrong, and you find out after the installation.
We ran this code over our own seven files, found two unusable ones and removed their numbers from the site. The same code sits here so you can check any file, ours or anyone else's.
What is not computed: UGR (it needs the room geometry and the observer position), type A and B photometry (floodlights and vehicle lamps), tilt from an external TILT file.