DIALux 4.3 is a free, professional lighting design software developed by DIAL GmbH. It allows users to calculate lighting levels (illuminance, luminance, glare, UGR, etc.) based on real photometric data from nearly every major luminaire manufacturer (Philips, Osram, Zumtobel, Eaton, etc.).
If you search for "Dialux 43," you will inevitably see results for Dialux Evo. It is vital to understand the difference before you download. dialux 43
| Feature | Dialux 4.3 | Dialux Evo | | :--- | :--- | :--- | | Modeling Style | Parametric (Room/Box geometry) | Free-form (Push/Pull) | | Learning Curve | Steep (Engineer focused) | Gentle (Architect focused) | | Calculation Speed | Very Fast (Legacy engine) | Slower on complex scenes | | Lighting Grids | Manual, precise point-by-point | Automatic, fluid | | Best For | Industrial, office, street lighting | Retail, residential, artistic | DIALux 4
Why do people still use Dialux 4.3? Because it is lightweight. It runs on old Windows 7 or XP machines, requires no GPU acceleration, and allows for absolute control over calculation points. For street lighting and emergency lighting (where specific lux values are mandated by law), version 4.3 is often faster and more accurate than Evo. Unlike Evo’s "working plane," Dialux 4
Unlike Evo’s "working plane," Dialux 4.3 uses explicit calculation surfaces. You draw a grid on the floor, wall, or ceiling, and the software calculates the lux at every intersection. This is essential for sports lighting (vertical illuminance) and emergency lighting (0.5 lux lines).
Solution: In the export settings, check the box "Export luminaire geometry as blocks."
Indoor offices suffer from glare. Dialux 4.3 contains a dedicated UGR module that calculates the psychological discomfort of lighting. You can place the observer at specific coordinates and run the UGR tabular method as defined by CIE 117-1995.