A Ritual Chamber silver-gelatin production still, 4:5 portrait: a near-empty slate institute chamber holds one black-glass idea mill beneath hard side light. It feeds identical narrow paper bridges onto a physical hexagonal lattice table, while a single irregular human-cut card rests outside the feed slot. Phosphor green #22c55e appears only as a short row of glowing index lamps. Large institute tile on the rear wall, deep shadow, clear analogue tube-amp warmth; a robed back-view archivist adjusts one brass comparator. Numbered callouts mark repetition feeder, contribution gauge, and stray card. One bridge is folded into an unnecessary perfect loop. Bureau seal struck once lower right. No caption text. Output in exactly 1122 x 1402 px, 4:5 portrait ratio.