Long Exposure Buddy

The long exposure calculator serious photographers actually use — ND filters, film reciprocity, golden hour, and a built-in timer. All in one app.

Long Exposure Calculator is the essential companion for photographers who shoot silky waterfalls, creamy oceans, light trails, star trails, and everything in between.

Calculate in seconds. Set your base shutter speed, choose your ND filter stops, and instantly see the corrected long exposure time. Exposure triangle mode lets you factor in aperture and ISO for complete creative control.

8 scene presets, ready to shoot. Whether it's a misty ocean at golden hour or spinning steel wool at midnight — tap a preset to load proven settings with expert tips for that specific scenario.

Built-in countdown timer. When your calculation is ready, tap Start. A full-screen timer counts down your exposure with Dynamic Island Live Activity support so you can track progress without unlocking your phone.

Film reciprocity failure correction. Shooting on film? Choose from 21 classic film stocks — Kodak Portra, Fujifilm Velvia, Ilford HP5, Tri-X, and more — and the app automatically calculates the extra exposure time needed to compensate for reciprocity failure.

Golden hour, always on. A location-aware banner on the main screen shows your next golden hour or blue hour countdown, updated in real time. A home screen widget keeps the timing front and center when you're planning a shoot.

Shot Log. Every calculated exposure is saved automatically. Search, browse, and export your shots as CSV for post-processing notes or location planning.

Filter Collection. Catalog your physical ND filters so the right stops are always one tap away.

Learn while you shoot. The built-in Education Mode covers ND filters, the exposure triangle, reciprocity failure, and scene-by-scene technique guides — no internet required. Siri Shortcuts. Ask Siri to open a long exposure calculation and jump straight into the app.

Designed for: Landscape photographers, architecture and cityscape shooters, astrophotographers, film photographers, and anyone learning long exposure technique.