Photometric Software Compared: AGi32, DIALux, Visual, and Web-Based Tools

The choice of photometric software shapes every downstream decision in a lighting design project: which IES files you can import, how accurately you can model complex geometry, whether you can export calculations to construction documents, and whether the output will hold up to scrutiny from an independent reviewer or a building department. Manual calculations — point-by-point illuminance using the inverse-square law and cosine correction — are sufficient for a single luminaire over a desk but completely inadequate for a multi-pole sports field, a curved parking deck soffit, or a retail space with hundreds of fixtures and a non-flat ceiling. You need software.

The problem is that the major photometric tools have meaningfully different strengths and weaknesses, different pricing models, and different levels of acceptance in different market segments and geographies. This comparison gives you the technical foundation to make that choice without discovering its limitations after you have already committed to a platform.

Why Software Accuracy Matters More Than You Think

Photometric software is not just a productivity tool — it is a claims generator. When you specify a lighting system based on a simulation that predicts 200 fc average with 0.70 uniformity, you are implicitly warranting that the installed system will deliver those values. If it doesn’t, the path leads to a dispute about whether the simulation was accurate, the fixtures were specified correctly, or the installation was commissioned properly.

Simulation accuracy depends on three things: the quality of the IES photometric data file for each luminaire, the accuracy of the room or site geometry model, and the correctness of the reflectance and surface properties assigned to all surfaces. Software accuracy differences between platforms mostly come down to how they handle complex geometry, how they implement inter-reflection calculations, and how faithfully they read and interpret IES file data.

Most major platforms implement radiosity (for interior inter-reflections) or ray-tracing (for more complex geometry) algorithms with comparable accuracy for typical applications. The differences appear at the edges: complex curved geometries, mixed interior/exterior models, and very large arrays with thousands of calculation points.

AGi32 by Lighting Analysts

AGi32 (pronounced “aggie 32”) is the dominant photometric calculation platform in the North American exterior and sports lighting market. Published by Lighting Analysts, Inc. in Colorado, AGi32 has been continuously developed since the early 1990s and carries a deep legacy of use in municipal street lighting, sports facility design, and transportation applications.

Technical Architecture

AGi32’s calculation engine uses point-by-point photometric computation based on luminous intensity data from IES files. For exterior applications, it computes horizontal, vertical, and semicylindrical illuminance at user-defined grid points using zonal cavity and direct-component methods. For interior applications, it adds a radiosity-based inter-reflection calculation that models light bouncing off walls, ceiling, and floor surfaces.

The software’s native file format is the ANSI/IES LM-63-19 photometric file — the same format used by virtually every North American luminaire manufacturer. AGi32 reads IES files directly, displays the intensity distribution in 3D polar plots, and applies them to fixtures placed in the model. The software also reads EULUMDAT (.ldt) files common in European photometric libraries.

Modeling environment: AGi32 operates in its own 2D/3D CAD environment that is efficient but not DXF-native. You can import DXF backgrounds as reference geometry and trace over them, but AGi32 is not a general-purpose CAD tool. For street lighting and sports field applications — where the geometry is typically flat planes and rectangular boundaries — this is not a significant limitation.

Calculation types: AGi32 supports horizontal illuminance, vertical illuminance (in four directions plus average), semicylindrical illuminance, cylindrical illuminance, mean spherical illuminance, and luminance. For sports lighting, the vertical illuminance calculation is critical for broadcast camera specifications; AGi32 handles this correctly.

Pole and fixture aiming: AGi32 has a dedicated exterior sports layout workflow that allows poles to be placed, fixtures assigned to pole positions, and individual fixture aiming angles (tilt and rotation) specified explicitly. The software reports deviation from IES recommendations and can calculate aiming for defined target points. This workflow is mature and tested against thousands of real projects.

Strengths

AGi32 is the gold standard for sports lighting photometric design in North America. When a project owner or electrical engineer asks for “an AGi32 study,” they are asking for the industry’s most recognized output format. The software’s ANSI/IES RP-6-24 sports lighting calculation workflow handles horizontal and vertical illuminance grids, uniformity calculations, and report generation in a format that is directly comparable to the standard’s requirements.

For roadway and parking applications, AGi32 includes built-in ANSI/IES RP-8-22 (street lighting) and ANSI/IES RP-20-14 (parking lot lighting) report formats that produce calculations in exactly the format that municipal reviewers and project owners expect. No other platform has this level of out-of-the-box compliance with North American standards.

Photometric data library: Lighting Analysts maintains an extensive online IES file database, and most North American manufacturers upload files directly. Finding the IES file for a specific sports fixture model is typically a two-minute task in AGi32’s library browser.

Limitations

AGi32’s BIM integration is limited relative to European platforms. There is no native Revit link or IFC import/export workflow. For projects where the lighting design needs to be coordinated with architectural models, exporting geometry from Revit to DXF and importing to AGi32 is the standard workaround — workable but not seamless.

Operating system: AGi32 is Windows-only. Mac users require Windows virtualization (Parallels, VMware) or a dedicated Windows machine. This is a real friction point for design teams standardized on macOS.

Cost: AGi32 is licensed desktop software with an annual maintenance fee. As of 2024, a new single-user license costs approximately $1,200–$1,500 with annual maintenance in the $300–$400 range. This is not prohibitive for a professional lighting design firm but represents a meaningful cost for a general electrical contractor or owner’s engineer who needs AGi32 for one project.

DIALux and DIALux evo

DIALux, published by DIAL GmbH in Germany, is the most widely used photometric software globally by installed user count. The original DIALux has been largely superseded by DIALux evo (the “evo” suffix distinguishes the architectural BIM version from the original room-based software). Both are available as free downloads.

Technical Architecture

DIALux evo builds lighting models in a full 3D architectural environment. You model the building — walls, floors, ceilings, windows, exterior surfaces — and then place luminaires, calculate illuminance, and evaluate results within that complete model. The 3D environment is significantly more capable than AGi32’s 2D/3D environment for complex interior geometry: curved ceilings, multi-story atriums, facades with complex profiles.

DIALux evo imports IES (LM-63) and EULUMDAT files, and also directly connects to manufacturer photometric databases through the DIAL Light Portal — a web service that serves photometric data from hundreds of manufacturers on demand without requiring you to find and download individual IES files.

BIM integration: DIALux evo imports IFC files, enabling coordination with Revit, ArchiCAD, and other BIM tools. Geometry built in a BIM authoring tool can be imported as a reference model, significantly reducing the time needed to set up complex architectural geometries.

DIALux Strengths

Free: The entire platform is available at no cost. This makes DIALux the default choice for small firms, individual consultants, and international markets where software budget is limited.

Interior commercial design: For office buildings, retail spaces, healthcare facilities, and other complex interior applications, DIALux evo’s 3D architectural modeling environment is genuinely superior to AGi32. The BIM workflow, inter-reflection accuracy in complex spaces, and render output make it the right tool for interior projects.

European standards compliance: DIALux evo has built-in support for EN 12464-1:2021 (interior workplace lighting), EN 12193:2018 (sports facility lighting), EN 13201 (road lighting), and other European standards. For European projects, DIALux report formats are exactly what owners and engineers expect.

Render quality: DIALux evo produces photorealistic renders of illuminated spaces using the Radiance or built-in rendering engines. These images are useful for client presentations and design review meetings.

DIALux Limitations

Exterior and sports lighting workflow: DIALux evo handles exterior applications, but its sports lighting workflow is less mature than AGi32’s. The pole placement, fixture aiming, and sports-specific calculation grids require more manual setup in DIALux than in AGi32, and the output report formats are less directly aligned with ANSI/IES RP-6-24.

ANSI/IES LM-63-19 handling: Some users have reported that DIALux evo’s handling of certain IES file variants (particularly older LM-63 formats with non-standard header data) can produce calculation discrepancies. For critical applications, validating a DIALux calculation against an AGi32 calculation using the same IES file is good practice.

Performance at large scale: Models with thousands of luminaires or very large exterior areas can be slow in DIALux evo. A 400-fixture stadium model with a fine calculation grid may require 20–60 minutes of calculation time on a typical workstation.

Visual Lighting Software

Visual (published by Acuity Brands) is a North American desktop photometric tool that competes most directly with AGi32 in the commercial interior and exterior lighting segments. It is sold as a licensed product, with pricing similar to AGi32.

Technical Architecture

Visual uses a combined direct-component and radiosity calculation engine for interior applications and a point-by-point engine for exterior applications. The modeling environment is more accessible to users without a CAD background than AGi32 — the workflow is more wizard-driven and less reliant on familiarity with the AGi32 CAD environment.

Visual has historically been stronger at commercial interior applications (offices, retail, industrial) than at sports or complex exterior work. The software integrates with Acuity Brands’ product catalog, which simplifies fixture specification for projects using Acuity products but adds friction when specifying competitive products that require IES file import.

Visual Strengths

Approachable interface: For engineers and architects who need to perform photometric calculations periodically but are not full-time lighting designers, Visual’s more structured workflow reduces the learning curve compared to AGi32.

Report quality: Visual produces professional calculation reports suitable for building permit submissions and construction documents.

Commercial interior workflows: Visual handles open-plan office, retail, and industrial high-bay layouts efficiently and accurately.

Visual Limitations

Visual is less commonly specified in the exterior and sports lighting community than AGi32. When a municipal engineer or sports venue owner asks for a photometric study, they are usually expecting AGi32 format output. Delivering a Visual report may require additional explanation.

The sports-specific workflow is less developed than AGi32’s. Multi-pole exterior stadium layouts require more manual configuration and the ANSI/IES RP-6-24 reporting format is not as native as in AGi32.

Windows-only, like AGi32.

Relux

Relux (published by Relux Informatik AG in Switzerland) is the dominant photometric platform in German-speaking markets and has significant penetration across Central Europe. It competes directly with DIALux in the European market.

Free in its basic version, with subscription tiers for advanced features. Like DIALux, Relux imports IES and EULUMDAT files and integrates with BIM workflows via IFC import.

Relux has a strong reputation for calculation accuracy, particularly in complex interior geometries. Its user interface is generally considered more polished than DIALux evo’s, though both platforms have improved significantly in recent years.

For North American users, the main limitation of Relux is its alignment with European standards (EN 12464-1:2021, EN 12193:2018) rather than IES standards, and its smaller install base in North America means that owners and reviewers may be less familiar with its output format.

Web-Based Photometric Tools

The lighting industry is moving toward browser-based photometric calculation tools that require no software installation and operate on any device. Several manufacturers and independent developers have deployed web-based calculators in recent years, ranging from simple room coefficient calculators to full 3D simulation engines.

Current Capabilities

Simple room calculations: Web tools handle single-room rectangular geometry well — calculate the number of fixtures needed to achieve a target illuminance in a defined space given a fixture’s efficacy and mounting height. These are essentially zonal cavity method calculations presented with a friendly UI. They are useful for preliminary sizing and for non-lighting-specialist users who need a quick check.

Manufacturer configurators: Many lighting manufacturers have deployed web-based tools that let you select a fixture family, input a room or space geometry, and receive a predicted illuminance result. These are convenient for specifiers evaluating a fixture family, though they typically only include that manufacturer’s products.

Full 3D web simulations: More capable browser-based tools implement real 3D calculation engines using WebGL and modern JavaScript. These tools can perform multi-fixture multi-surface calculations comparable to desktop software, but they currently lack the mature workflow tools (pole aiming, ANSI/IES RP-6-24 report generation, DXF background import) that make AGi32 and DIALux viable for full project deliverables.

Accessibility Advantages

Web-based tools offer genuine advantages over desktop software:

• No installation: a project owner, general contractor, or field technician can run a calculation check from a browser on a tablet at the job site without installing software.
• Always current: web tools update automatically; there is no “version mismatch” problem when sharing files between team members.
• Collaborative: multiple users can access the same project simultaneously, which is valuable for design review workflows.
• Cross-platform: browser-based tools run equally on Windows, Mac, Linux, iPad, and Android.

Current Limitations

Current web-based tools have not yet matched the depth and workflow completeness of mature desktop platforms. AGi32’s 20+ years of sports lighting workflow development, ANSI/IES RP-6-24 reporting, and pole aiming calculation represent a capability gap that web platforms are working to close but have not yet closed.

Performance is also a consideration: complex exterior simulations with hundreds of fixtures and fine calculation grids push the limits of browser-side computation. Desktop applications with access to full CPU and memory resources still have a performance advantage for large-scale calculations.

Comparison Table

Feature	AGi32	DIALux evo	Visual	Relux	Web-Based
Cost	~$1,200–$1,500 + maintenance	Free	~$1,000–$1,400 + maintenance	Free / subscription	Free–subscription
Operating System	Windows only	Windows, Mac	Windows only	Windows, Mac	Any (browser)
BIM / IFC Integration	Limited	Strong	Moderate	Strong	Varies
Sports/Exterior Workflow	Excellent (best-in-class)	Good	Moderate	Good	Limited
Interior Commercial	Good	Excellent	Excellent	Excellent	Moderate
ANSI/IES RP-6-24 Reports	Native	Manual	Limited	Manual	N/A
EN 12193:2018 Reports	Manual	Native	Manual	Native	N/A
Per-Fixture IES Library	Extensive	Extensive (DIAL Portal)	Acuity-centric	Extensive	Varies
Roadway (RP-8)	Native	Good	Good	Good	Limited
Render Quality	Low	High	Moderate	High	Varies
Large-Scale Performance	Fast	Moderate	Moderate	Moderate	Limited
Collaboration	None (file sharing)	None (file sharing)	None	None	Built-in (some tools)

How to Choose: Project Type and Team Workflow

Choose AGi32 for sports lighting, exterior area lighting, roadway lighting, or parking design in North America. If your clients are municipalities, schools, or sports venue owners who will compare your calculations to a peer review, AGi32’s output format is the one they recognize and trust.

Choose DIALux evo for interior commercial projects in any geography, for BIM-coordinated building projects, or for any project with a European EN-standard specification requirement. The free cost makes it a low-risk addition alongside AGi32.

Use both: many professional lighting designers maintain licenses for both AGi32 and DIALux evo, using each where it is strongest. The two-software approach is the industry norm for firms working across both sports/exterior and commercial interior projects.

Consider web-based tools for preliminary design checks, collaboration with non-specialist team members, and owner-facing interactive design reviews. Web tools are not yet replacements for desktop software on complex projects, but they are valuable supplements.

The Future: Cloud Photometric Platforms

The lighting industry is converging toward cloud-based photometric platforms that combine the calculation accuracy of desktop tools with the accessibility and collaboration features of web applications. Several well-funded startups and established software companies are working on full-featured cloud photometric engines.

The advantages of a cloud platform are compelling: automatic IES file management (connected directly to manufacturer databases), real-time collaboration on the same project model, calculation results accessible on any device, and API integration with design tools and BIM platforms. The performance bottleneck — complex 3D radiosity calculations are computationally intensive — is addressed by offloading calculation to server-side compute rather than the client browser.

The desktop photometric platforms have served the industry well for 30 years. The next generation of cloud-native tools is being built now, and the firms that understand the strengths and limitations of today’s tools will be best positioned to evaluate and adopt the next generation when it arrives.