Calculate ND filter exposure times – precisely, quickly, in the field. The complete ND filter calculator for photographers, drone pilots and videographers. Seven specialized calculation modes for every shooting scenario. Whether you stack filters for a seascape, fly a DJI drone, or shoot long-exposure video – get the right exposure time in seconds. 7 CALCULATION MODES – Simple: shutter speed + ND filter = new exposure time – Expert: combine aperture, ISO and up to 5 filters at once – Bulb: long exposures in hours, minutes, seconds – Reverse ND: pick your target shutter speed, get the matching filter – Light / EV: filter based on aperture and ISO – Drone: frame-rate based calculation (180° shutter rule) – Vario ND: calculations for variable ND filters BUILT-IN EXPOSURE TIMER Tap your result to start the timer. Runs as a background service, alerts you with sound and vibration. No stopwatch needed. FAVORITES & CUSTOM FILTERS Save your go-to setups per calculation mode. Search, sort and filter for instant access. Create custom ND values for your specific gear (Tiffen, K&F, Lee, Haida, NiSi, PolarPro and more). LEARN AS YOU SHOOT Full tutorial, step-by-step guides, and a real-world FAQ with 11 practical questions. Accessory recommendations for tripods, step-up rings and filter brands. ALL FEATURES – 7 specialized calculator modes – Stack up to 5 ND filters – Dedicated Drone Mode – Built-in exposure timer – Custom ND filter values – Full tutorial and FAQ – Night mode / dark theme – Screen lock during exposure – 27 languages – Privacy first, no unnecessary permissions GO PREMIUM Remove ads, unlock unlimited favorites and get full access to every mode. Or download "ND Filter Expert Pro" as a standalone paid app. Questions or feedback? [email protected]