Two ways, one button
If your phone maker offers a Night mode to apps (many Samsung, Xiaomi, OPPO, vivo and Honor phones do), Lens uses it.
Otherwise Lens takes 4 to 8 quick shots, picks the sharpest as the reference, lines the others up and averages them. That cuts noise by around 3 times while keeping detail.
No ghosts, full resolution
Anything that moved between shots, like a person walking past, is left out of the merge so it doesn’t turn into a see-through ghost. The result is saved at your camera’s full resolution.