Question 1

Why would you add noise to a photo?

Accepted Answer

Three reasons: it imitates film stock for an analogue look, it masks banding in smooth gradients like skies, and it stops an over-smoothed or AI-upscaled image from looking plastic.

Question 2

What is the difference between grain and noise?

Accepted Answer

Grain is the silver crystal structure of film and is monochrome, so it reads as texture. Digital noise is per-channel and shows as coloured speckle, which looks like a fault. This tool applies the same value to all three channels, which is why it reads as grain rather than noise.

Add grain or noise to a photo