Light Ruler: Photo Toolkit

Light Ruler is a local-first photography calculator designed for iPhone. It is useful for landscape, long exposure, night sky, and everyday exposure planning. You can quickly calculate: - ND filter long exposure shutter speed - Equivalent exposure for aperture, shutter, and ISO changes - Depth of field, near limit, far limit, and hyperfocal distance - Maximum night sky shutter before visible star trails - Angle of view and equivalent focal length across sensor formats Light Ruler does not require an account, does not connect to a backend, and does not actively make network requests. Camera profiles, lens profiles, and saved calculations are stored locally on your device. Useful for: - Long exposure with ND filters - Night sky shutter planning - Landscape depth of field and hyperfocal checks - Comparing focal length behavior across sensor formats