GlassMeter: Film Light Meter

GlassMeter shows you the photograph before you take it. Spot-meter any tone, place it on the Zone System, and watch your film — Portra, Tri-X, Velvia and 27 more — render live in the finder. Everything happens on your iPhone. THE METER • Spot, average and incident metering (incident uses the front camera) • Multi-spot Zone workflow: pin a shadow and a highlight, and GlassMeter places the exposure between them • Place your spot reading on Zone III, IV, V or VI, and hold it with AE-L • Scene Range marks the darkest and brightest parts of the frame and the stops between them, so you know whether the scene fits your film • An 11-zone histogram, exactly one stop per zone, with RGB curves on color film • LiDAR rangefinder on iPhones with LiDAR: subject distance and live depth-of-field limits for your aperture • Calibrate to your handheld meter in seconds THE FILM • 30 stocks modeled on manufacturer datasheets: Portra, Ektar, Gold, Ektachrome, Tri-X, T-MAX, HP5 Plus, FP4 Plus, Pan F Plus, Delta, XP2, Velvia, Provia, Acros II, CineStill, Double-X and more • Each with its own characteristic curve: Portra's long highlight shoulder, T-MAX's straight line, Velvia's deep shadows • Push and pull, with grain and contrast that shift as they do in the darkroom • Reciprocity failure for every stock, from the published correction data • Halation true to the film: CineStill blooms, black-and-white barely glows THE CAMERA • Aperture and shutter dials with haptic detents. Lock one, and METER solves the other • 15 classic medium-format lens profiles from the Zeiss V-system, each with its true field of view and vignetting • Contrast filters (Y8, G11, O21, R25), color conversion filters and a full ND set to ND1000, each with its exposure factor • Bulb mode: a metered long exposure, corrected for reciprocity, with a countdown timer THE FRAMES • Every frame is developed by the same 16-bit wide-gamut film pipeline as the finder, so the look you composed is the image you keep • A notebook that keeps itself: each frame records its film, lens, aperture, shutter, ISO, push/pull and spot readings • Contact sheet and negative views: color negatives with their orange mask, black-and-white on a clear base • Share the photo, or a film-frame card with edge markings and the exposure • EXIF records the body, lens, film, aperture and shutter you used • Save to Photos and location tagging are optional and off by default PRIVATE BY DESIGN No account. No analytics. No AI. GlassMeter runs entirely on your iPhone and collects no data; its App Privacy label reads "Data Not Collected." Photos and location access are optional, and your frames stay yours. GlassMeter is an independent app, not affiliated with any camera or film manufacturer. All trademarks belong to their respective owners.