LumiSnap

LumiSnap automates high dynamic range (HDR) image capture and produces detailed luminance maps for architecture, building science, daylight analysis, and lighting design. Capture multiple exposures, combine them into HDR images, and calibrate using readings from a separate spot luminance meter. Explore light distribution through color-coded maps, interactive luminance readings, and histograms. Capture, processing, analysis, and export work directly on iPhone. CAPTURE • Adaptive exposure brackets, with Bayer RAW on supported devices and lenses • Ultra Wide, Wide, and Tele lens selection where available • HDR time-lapse: 2–999 sessions, intervals from 1 second to 24 hours, optional scheduled start • Frame alignment and ghost reduction for small camera movement and moving people • Apple Watch remote trigger with capture progress and stop control CALIBRATE Calibration requires a separate physical spot luminance meter, such as one from Konica Minolta or Sekonic, to measure reference surfaces in cd/m². Enter the readings manually at matching image points and review calibration fit diagnostics. Without meter calibration, luminance values are estimates; you can still capture, explore, and export images. EXPLORE • Color-coded luminance maps with linear or logarithmic ranges • Turbo, Inferno, Magma, and Viridis color ramps • Tap the image to inspect calibrated or estimated luminance • Luminance histogram using the selected color ramp, with the display range marked • Coverage view showing clipped, too-dark, and uncertain pixels EXPORT AND DESKTOP ANALYSIS • Radiance HDR (uncalibrated or calibrated) and full-resolution false-color PNG with legend • Portable session ZIPs with RAW originals for LumiSnap Desktop • Optional iCloud Drive sync for access to completed sessions on your Mac iCloud Drive sync uses your Apple Account and iCloud storage. Deleting or moving a synced session out of the LumiSnap folder in iCloud Drive also removes that session from the iPhone. BUILT FOR ARCHITECTURE EDUCATION AND RESEARCH Used in architecture teaching at Cornell University and MIT, LumiSnap supports lighting and daylighting education, research, and professional practice. It was created by Timur Dogan, Associate Professor of Architecture at Cornell University and director of the Environmental Systems Lab. Learn how to plan an exposure bracket, take reference measurements, and use HDR images for daylight studies with the illustrated field guide at https://lumisnap.io/guide.html. PRACTICAL REQUIREMENTS For best results, use a tripod to keep the iPhone fixed throughout each exposure series and time-lapse. Keep LumiSnap open during a time-lapse. Capture capabilities depend on device, lens, and iOS version. For Apple Watch remote capture, keep LumiSnap open on the unlocked, paired iPhone. LumiSnap does not replace a calibrated spot luminance meter. Physical validation of the capture and calibration setup is required for quantitative measurement.