Tonal conversion / runs locally
Turn a colour photograph into black and white the way it was done on film — with a filter over the lens and a paper grade under the enlarger. Your picture is processed by this page in your own browser and is never uploaded anywhere.
Drop a photograph here
or click to choose · paste with Ctrl+V · JPEG, PNG, WebP
Panchromatic film records all colours as grey, so a red barn and green grass can land on the same tone. Photographers put a coloured filter on the lens to pull them apart. The same maths applies here.
Darkroom paper came in contrast grades from 0 to 5. A soft grade holds detail in a harsh negative; a hard grade puts life back into a flat one. The slider applies the equivalent curve.
Ansel Adams divided the tonal range into eleven zones. The strip above fills with where your picture actually sits, so you can see whether the shadows are blocked or the highlights blown.