**Chat log** from Bead: Through The Lens Campanile · [canonical source](https://redfish.acequia.io/guerin/.agents/7610bb17-52c1-4e5b-991b-16d61e06ed46/2026-06-16/chats/2026-06-16-through-the-lens-campanile.md) · session 2026-06-16 · discussion: Talk: Through The Lens Campanile *Verbatim chat log: immutable provenance. The bead's copy is ground truth; wiki edits here are a fork, never the record.*
## Pre-bead context - Hatched out of `#image-pose-uxui` (`74c30681`): Stephen answered that bead's dashboard question (q-90s) — "search the beads, naimark gave a google tech talk on viewfinder" — which led to finding `dev/team/owen-duncan/image-match/`. IDE had `campanile-camera-calibration.md` open.
## Turn 1 — hatch (verbatim) > start-bead through-the-lens-campanile > document the goal and approach > index the documents in the folder for future reference. > do deep search of modern approaches to through the lens calibration **Assistant:** Scaffolded this bead (about/README/bind-startup/names + this log). Wrote [notes/00-goal-and-approach.md](../notes/00-goal-and-approach.md) (goal + the two paradigms: differential Gleicher–Witkin TTL vs. discrete LM resectioning) and [notes/01-document-index.md](../notes/01-document-index.md) (catalog of the image-match folder: Naimark Viewfinder talk LRAj21y23r8, Gleicher TTL paper+video aPraFT6JilE, campanile-camera-calibration.md, plan.md — with key timestamps). Read `plan.md` (a three.js Gleicher–Witkin TTL demo spec) to index it accurately. Launched the **deep-research** skill for a survey of modern through-the-lens / interactive camera-calibration approaches → [notes/02-modern-ttl-survey.md](../notes/02-modern-ttl-survey.md).