Zemax, CODE V, and LightTools: How the Three Major Optical Design Tools Differ — and How to Choose
1. Introduction
In the world of optical system design, nearly every professional engineer runs into three commercial software packages: Zemax OpticStudio, CODE V, and LightTools. All three can do ray tracing, modeling, and optimization, but their historical positioning, the types of tasks they excel at, and their target users differ noticeably.
Before diving into the comparison, there's a piece of background worth clarifying: all three tools now technically belong to the same company. Zemax is currently an Ansys product (branded "Ansys Zemax OpticStudio"), while CODE V and LightTools have long been part of Synopsys's optical solutions lineup. On July 17, 2025, Synopsys completed its acquisition of Ansys, in a deal valued at roughly $35 billion. That means all three product lines — Zemax, CODE V, and LightTools — now sit under Synopsys. That said, they continue to be sold and maintained as separately positioned, independent products rather than being merged into one tool. So the choice should still be based on the task at hand, not on which company happens to own the software.
Below is a comparison across positioning and history, technical characteristics, typical users, and use cases, followed by practical guidance on how to choose.
2. Positioning and History
2.1 Zemax OpticStudio
Zemax was originally developed by Ken Moore in the 1990s and has long been known for being cost-effective, user-friendly, and quick to learn. It has one of the largest user bases of any optical design software worldwide, with especially strong adoption in universities, startups, and small-to-mid-size optical teams. It supports both sequential and non-sequential ray tracing, which in theory lets it handle both imaging lens design and a portion of illumination/stray-light analysis, giving it fairly broad coverage. Since being folded into Ansys, it has gained tighter integration with Ansys's broader multiphysics simulation ecosystem (structural, thermal, electromagnetic).
2.2 CODE V
CODE V was developed by Optical Research Associates (ORA) and later acquired by Synopsys. It's one of the longest-running commercial optical design tools on the market, with roots tracing back to 1963. Within the industry, CODE V has long been regarded as the gold standard for imaging optical design: its optimization algorithms, tolerancing capabilities (including its well-known Glass Expert smart glass-selection feature), and macro language (SCP/Macro-PLUS) are widely considered deeper and more flexible than comparable tools — particularly for complex, large-scale, ultra-high-precision imaging systems such as satellite remote-sensing lenses, lithography objectives, and large astronomical optical systems, where it's the preferred choice for many leading optics companies and research institutions. The trade-off is a steeper learning curve and, traditionally, a higher price point than Zemax.
2.3 LightTools
LightTools is also part of Synopsys's optical solutions lineup, but its positioning is entirely different: it's a dedicated tool for non-imaging (illumination) optical design. Its core use cases are LED lighting, automotive headlights/taillights, backlight units, light guides, displays, AR/VR optics, and fiber-optic illumination. LightTools' strengths lie in the scale and speed of its non-sequential ray tracing, its library of real-world light sources and material properties (the SmartStart Library), and the depth of its photometric/radiometric analysis (illuminance, luminance, chromaticity, etc.) — areas where Zemax's non-sequential module is comparatively weaker. Synopsys has continued to strengthen interoperability between CODE V and LightTools (CODE V's surface-based models can be converted directly into LightTools solid models), making it easier to co-simulate complex systems that contain both imaging and illumination components.
3. Multi-Dimensional Comparison
| Dimension | Zemax OpticStudio | CODE V | LightTools |
|---|---|---|---|
| Current owner | Ansys (folded into Synopsys in 2025) | Synopsys | Synopsys |
| Core positioning | General-purpose optical design (mainly imaging, some non-imaging) | High-end imaging optical design | Specialized illumination / non-imaging optical design |
| Ray-trace modes | Sequential + non-sequential | Primarily sequential (basic non-sequential capability) | Primarily non-sequential |
| Optimization engine | Solid, covers routine-to-moderately-complex tasks | Widely regarded as the strongest, built for complex large systems | Focused on illumination system optimization (e.g., light-distribution curves) |
| Tolerancing | Comprehensive, covers typical industrial needs | Very deep, includes smart tools like Glass Expert | Focused on optical-mechanical assembly tolerances |
| Scripting / automation | ZOS-API (.NET/Python/MATLAB, etc.) | Macro-PLUS/SCP macro language, very mature | Built-in scripting (Basic/Python interfaces) |
| Learning curve | Relatively gentle | Steeper — deep functionality that takes experience to master | Moderate — tailored to illumination engineers' workflows |
| Typical users / industries | Universities, startups, small-to-mid teams, consumer optics, general lens design | Aerospace/defense, lithography, large optical-systems integrators, high-precision imaging manufacturers | Automotive lighting, displays/backlights, LED lighting, architectural lighting, AR/VR |
| Ecosystem interoperability | Integrated with Ansys's multiphysics toolchain (structural/thermal/EM) | Interoperable with LightTools for combined "imaging + illumination" design | Interoperable with CODE V |
| Price positioning | More accessible, strong value for money | Traditionally priced higher, aimed at enterprise budgets | Quote-based; often more cost-effective when bundled with CODE V |
(Note: exact pricing should be obtained directly from the vendor for the latest terms. The table above reflects long-standing, widely recognized relative positioning in the industry rather than an official price commitment.)
4. How to Choose
The flowchart below summarizes a simplified decision process:
In more detail:
Lean toward Zemax OpticStudio if:
- Your team is small, or you're an individual, student, or startup with a limited budget;
- Your work is primarily conventional imaging lens design (camera modules, surveillance lenses, endoscopes, general optical instruments) without extreme tolerancing or massive-system requirements;
- You want a single "all-rounder" tool that can handle imaging as well as some stray-light/non-imaging analysis, rather than buying separate software for each task;
- Your team has many newer members and needs a lower learning curve along with abundant teaching resources and community examples.
Lean toward CODE V if:
- You work in aerospace remote sensing, defense, semiconductor lithography, large astronomical/scientific instruments, or another field with extremely demanding optical performance and tolerancing requirements;
- Your system is structurally complex (many elements, dense aspheric/freeform surfaces, mixed reflective-refractive configurations) and needs the industry's strongest automatic optimization to converge on a feasible solution;
- Your team includes experienced senior optical engineers who can make full use of the macro language and advanced features, and is willing to accept a steeper learning curve and higher cost for that added capability;
- You need a rigorous, auditable tolerancing workflow (for example, yield prediction geared toward mass production and supply chains).
Lean toward LightTools if:
- Your core task is illumination or non-imaging optics — automotive lighting (low/high beam, daytime running lights), LED fixtures, display backlight units, light guides, fiber-optic illumination, architectural lighting, and the like;
- You need precise photometric/radiometric analysis (light-distribution curves, illuminance distribution, chromaticity uniformity, etc.), and want real light-source and material property libraries to make the simulation more credible;
- Your system involves very complex optical surfaces/structures and a huge volume of non-sequential rays (illumination simulations often require tracing hundreds of millions or even billions of rays), requiring a solver specifically optimized for that.
Consider combining CODE V + LightTools if:
- Your system contains both imaging and illumination components that interact with each other — think heads-up displays (HUDs), AR/VR optical modules, or an integrated automotive camera-plus-ambient-lighting module;
- You need, within a single project, to first complete a high-precision imaging optical path in CODE V, then import the model into LightTools for illumination/stray-light/appearance simulation, with data flowing seamlessly between the two for iterative co-design.
5. Summary
The relationship between these three tools isn't simply "which one is better" — each is rooted in a different niche. Zemax OpticStudio is the broadest-coverage, best-value general-purpose choice; CODE V is the benchmark tool for high-end imaging optical design; and LightTools is the specialist choice for illumination and non-imaging optics, often paired with CODE V to cover complex systems that need both imaging and illumination. Although all three now sit under Synopsys as of 2025, they remain independently maintained and independently priced product lines. When choosing, it's best to first clarify your task type, team capability, and budget, then weigh them against the comparison table and decision logic above — and if you're still unsure, you can always reach out to the vendor for an evaluation license and try it on a real project before deciding.