Enlarging
Enlarger, lens, contrast filters — turn a 35 mm frame into a wall.
From frame to wall
The enlarger projects your negative through a lens onto multigrade paper. A contrast filter decides how punchy the print gets.
The controls
contrast grade 0 (flat) → 5 (hard) exposure seconds, via a timer size head height + lens focus grain-focuser, sharpest point
The grade
Print a flat scene at grade 4, a contrasty one at grade 1. The filter is how you rescue a negative that the film underexposed.