Andrew Lawrence, 45, took snaps of women from his first-floor flat on St Swithin Street in Aberdeen.
Police uncovered 71,600 images on his laptop and camera when they confronted him following a tip-off.
The photographs were taken over a two-year period between August 18, 2009, and June 30, 2011.
Lawrence pled guilty to one charge of breach of the peace at Aberdeen Sheriff Court.
Sentence was deferred to February 27.