Reciprocity Timer

Reciprocity Timer is a film photography exposure calculator and timer made for long exposures. It corrects reciprocity failure per film stock, compensates ND filters, and times your shots so you can capture sharp night scenes, silky water, and streaking clouds with confidence. Core features include film-specific reciprocity correction with custom curves, ND filter and bellows extension compensation, and a precise countdown timer with vibration alerts and shot logging. Fast, reliable, and offline-ready, it is a practical long exposure, reciprocity, and ND filter calculator for photo and video creators seeking consistent results on location.