Add Grain to a Photo

The mistake that costs you the grain entirely

Grain is drawn one value per pixel, at whatever resolution the editor is working at — your photo's own, or 4096 on the long edge if it was larger than that. Export at 1080 from a twelve-megapixel original and every output pixel becomes an average of several input pixels, and averaging random noise is precisely how you remove it. The grain you judged at full size arrives noticeably weaker.

Exporting at Original does not avoid this, it only hands the resizing to whoever displays the photo next, and a social platform will shrink it just as effectively. The thing that actually helps is deciding the final size first and then judging the grain at that size rather than at 100% zoom — or, if you already know the picture is going somewhere small, pushing the slider past what looks right on screen so something survives the trip.

What the even spread costs you

The noise is generated at one amplitude for the whole frame, without reference to how bright any part of it already is. What you actually see is a little more forgiving than that sounds, because values are clipped at pure black and pure white afterwards, which starts to eat the noise itself at the extremes. At exactly white only the half that would brighten is clipped, leaving grain that can darken but not lighten; on a pixel the other sliders have already pushed well past white, both halves go and the texture disappears entirely. Still, the simplification is real: film grain is most apparent through the midtones and tapers off where the emulsion is nearly clear or nearly saturated, and a flat amplitude does not reproduce that taper.

In practice it costs least on ordinary photographs and most on high-contrast ones. If your picture is mostly midtones you will not be able to tell. Where it shows is the range just short of blown or just short of black, which carries more texture than film would have put there, and the honest fix is less grain overall rather than expecting the slider to know the difference. The 35mm film page covers how this differs from digital sensor noise, which is a separate question again.

Where grain goes next

Grain rarely finishes a photo on its own. It pairs most naturally with softness, because real grain sat on images that were never perfectly sharp, and with a little fade. For the whole recipe rather than this one slider, see how to make a photo look old. For grain in its most natural home, the 35mm film filter uses 25 with the colour left close to neutral. And grain suits black and white better than almost anything, since without colour the texture has room to be the subject.