RE: [Demo notebook] QC clinic: photographic evidence and its limits · RWI-24037

[BenchNotes 00261]

Case 20 — Disputed observation: is this dial colour shift real or just lighting?

The difficulty is that phone cameras adjust white balance automatically, and blue dials are especially sensitive. Two photos of the same dial under different light can easily look like a 'batch difference'. Any comparison needs both dials in the same frame, under the same light, ideally next to a neutral grey or white reference card.