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LBZF Design Docs

Amcrest IP8M-2779EW-AI varifocal cameras, not Dahua IPC-HDW2849T-S-IL

Context

Section titled “Context”

The v1.9 pre-deployment plan (locked 2026-04-27) specified 6× Dahua IPC-HDW2849T-S-IL 8MP fixed-lens PoE dome cameras for Phase I, sourced from Nelly’s Security or eBay (Dahua-from-Amazon was flagged as gray-market risk). Phase I targets one module (Angela) with workstation-level cycle monitoring.

Two problems surfaced before purchase:

  1. Fixed focal length required knowing module geometry in advance to pick the right lens. We don’t — final camera placement depends on on-site mounting points and FoV constraints in Pereira, which can’t be measured until install day.
  2. Sourcing friction — Nelly’s Security lead times and Amazon-Dahua gray-market risk made the procurement path slower and less reversible than needed.

Decision

Section titled “Decision”

Use 2× Amcrest IP8M-2779EW-AI varifocal turret cameras (2.7–13.5mm) for Phase I, sourced from Amazon (returnable).

Why these:

  • Varifocal lens — Ronald can frame each workstation on-site without us pre-picking a focal length.
  • Dahua-rebadge — same underlying sensor and stack as the original v1.9 pick, so no fundamental tech change.
  • Built-in AI human/vehicle detection on-camera — reduces some load on the Jetson and gives a fallback detection signal.
  • Amazon-returnable — Phase I procurement stays reversible until install.

Consequences

Section titled “Consequences”
  • Phase I camera count: 2 (not 6). Phase I will instrument fewer workstations than v1.9 envisioned. Ronald picks which two are highest-value to instrument first. Phase II / III scale.
  • Security hardening required. Amcrest devices have a history of CVEs (CVE-2025-31700, CVE-2020-5735) and phone-home behavior. The install runbook must: air-gap the camera VLAN, disable Amcrest Cloud / P2P, block outbound ports 37777 / 80 on the camera VLAN.
  • Future re-evaluation. If Phase II behavioral monitoring requires fixed focal lengths or different optics, re-open this decision.

References

Section titled “References”
  • Memory: hardware finalized 2026-05-11
  • Superseded text in docs/design/40-prototype/hardware/README.md (currently marked stale)