# Independent check of ghost-path enumeration on 10 lens designs

Canonical: https://www.formlightoptics.com/portfolio/ghost-path-enumeration-cross-check
Markdown: https://www.formlightoptics.com/portfolio/ghost-path-enumeration-cross-check.md

Checked a sequential ghost-path method against OpticStudio on 10 imaging lens designs, from a singlet through a 100° wide-angle and a zoom.

Simulation, stray light (method study). 2026 Q4.

Capabilities: Simulation, Stray light.

### Challenge

Standard sequential ghost operands cannot model a reflection between a lens surface and the sensor. A sequential ghost-path enumerator still has to match OpticStudio on the paths both methods can see.

### Approach

An independent ghost-analysis tool enumerated two-bounce ghost paths on the same 10 imaging lens prescriptions used in Zemax OpticStudio. The designs ran from a singlet through a 100° wide-angle and a zoom. Custom programs and scripts compared the path lists and the ghost-focus positions.

### Result

The check enumerated the same two-bounce ghost paths as OpticStudio on every design, about 450 paths in all. The largest ghost-focus position difference was under 0.2%. Lens-to-sensor reflection ghosts ranked in the top 5 on 9 of 10 designs.

### Key figures

- ~450: two-bounce ghost paths matched to OpticStudio on every design
- <0.2%: largest ghost-focus position difference versus OpticStudio
- 9 of 10: designs where lens-to-sensor ghosts ranked in the top 5

Tools: Zemax OpticStudio, custom programs and scripts.

Related services: [Zemax OpticStudio consulting](https://www.formlightoptics.com/services/zemax-opticstudio-consulting), [Stray light and non-sequential simulation](https://www.formlightoptics.com/services/stray-light-and-non-sequential-simulation).