# Stray light and non-sequential simulation

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Non-sequential analysis of ghosts, flare, and light a model fails to account for.

Published checks have included a ghost screen of internal reflections, flare at the sensor, stray light relative to incident light, and off-axis glare for a detection task. A fiber model also showed that default ray-trace limits can drop launched light without a warning. A luminaire stray-light study is handed off as a named non-sequential model plus a report.

Fixed-fee projects. Scope, deliverables, and price are agreed in writing before work starts.

### Typical problems

- Internal reflections put a ghost or a flare peak on the sensor.
- A design needs those ghost paths ranked, including lens-to-sensor reflections that standard sequential ghost operands cannot model.
- Stray light has to be stated relative to the light that should arrive.
- Off-axis glare has to be scored for a sensor, not only as a lens MTF.
- Default ray-trace limits can drop launched light and leave the energy budget open.
- A luminaire needs a stray-light model in a named non-sequential tool.

### Deliverables

- A report of ghosts, flare, or energy balance, with assumptions labeled
- Native files, not screenshots
- A written report of assumptions, methods, results, and recommended next steps, for internal review or a vendor RFQ.

Tools: FRED, TracePro, and Zemax OpticStudio.

### Related case studies

- [Independent check of ghost-path enumeration on 10 lens designs](https://www.formlightoptics.com/portfolio/ghost-path-enumeration-cross-check)
- [Placement-tolerant optics for a smartphone dermatoscope](https://www.formlightoptics.com/portfolio/smartphone-dermatoscope-placement-robustness)
- [Imaging lens for a 4K otoscope](https://www.formlightoptics.com/portfolio/4k-otoscope-imaging-lens)
- [Image quality and detection toolkit for space optics](https://www.formlightoptics.com/portfolio/space-sensor-image-quality-toolkit)
- [Energy audit of a side-glowing fiber model](https://www.formlightoptics.com/portfolio/side-glowing-fiber-energy-audit)
- [Laser light delivery for a diagnostic test cartridge](https://www.formlightoptics.com/portfolio/diagnostic-cartridge-laser-delivery)