6.5.1 · Photos, Video and Measuring
Measuring Basics
What you can measure, reading points, saving and sharing.
What you can measure: Expect about 1% accuracy within a few meters.
Any LiDAR photo or LiDAR video, yours or one a teammate shared, on any iPhone. Open it and tap Measure on the bottom bar (a video pauses on the nearest depth frame). Pick a tool with the icons below the picture. Distances are real 3D distances from the LiDAR depth; level and vertical come from gravity, so they're true even if the phone was tilted.
Best within about 3 m. On a flat wall a few meters away, expect about 1%.
On ThermDAR shots: Real sizes on the heat picture.
A ThermDAR photo or video has both sets on the tool line: Temperature and Measure. Measure taps on the heat picture land on its LiDAR depth through the FLIR alignment, so you can measure how wide a cold patch is or how far apart two warm spots are. If the FLIR isn't aligned the line says so: Overlay (shots taken before aligning work once it's saved). Switch to iPhone to measure on the LiDAR photo itself.
Reading the points: Spot a tap that hit the background behind an edge.
Points are lettered A, B, C. The small italic number under each is how far it was from the phone. If one point reads much farther than its neighbors, it probably hit the background behind an edge: tap a little further in.
When a tap is refused: Fixes for every message, and photos that can't be measured.
- No depth here: try a closer or less shiny spot. The dot turns gray.
- Low LiDAR confidence here (video): tap a closer or flatter spot.
- Points are in a line: spread A, B and C out (Angle and Area).
- Outline crosses itself: tap the corners in order around the edge.
- No usable depth or depth is relative: that photo can't be measured (for example some portrait photos).
Height and Angle need the gravity saved with the photo, so they're hidden on older or imported photos without it.
LiDAR video frames: Measure from something in one frame to another.
While measuring a clip, a row of buttons sits above the scrub bar:
- Previous / Next frame: step one depth frame back or forward.
- Next bookmark: jump to the next moment you marked while filming.
- Sharpest (the aperture): find the sharpest frame nearby.
- Overlay: off, depth (red near, blue far), or LiDAR confidence (green good, yellow fair, red poor).
Points stay put when you change frame, so you can measure from something in one frame to something in another. Play is off while measuring.
Save and Clear: A tick flash confirms each one is kept.
The bar reads Save, tools, Clear. Save (box with a down arrow) lights up once there's a readout and keeps it exactly as shown, as a Measure note on the photo's station or pin (Save Measurements and Notes). A tick flashes when it's saved. Clear (the eraser) removes the points.
Share it: Even iPhones without LiDAR can measure what you send.
Share a LiDAR photo and the depth and gravity go with it, so whoever gets it can measure too. A LiDAR video shares as a .speleovideo file with its depth frames. iPhones without LiDAR can't take LiDAR photos or video, but can measure ones a teammate shares.
Mentioned in: 5.2 View and Measure · 9.10 Media