[amelius]

But with enough depth (bits), almost every pixel will be changing at high frequency due to small light variations.

[b112]

Which probably indicates some algorithmic way the chip determines true, non-light based change.

Yet, this also means the possibility of some missed changes, of some changes being taken as lighting changes, instead of object change.

Was that a cloud, or a large shape close to the lens?

Hmm. Gonna have to read on this.