Test method · Version 1.0
How to test an automatic camera trigger.
A trigger can notice an event and still miss the photograph. This method separates detection from camera readiness and completed capture, records false positives, and keeps every result tied to the device and conditions that produced it.
The principle
Count the chain, not just the flash.
For every planned event, record whether the app detected it, whether it requested a capture, whether the camera completed that capture, and whether the saved image contains the intended moment. A single “worked” score hides where failure occurred.
No benchmark is claimed here. This is a protocol for future testing. It contains no synthetic success rate, no competitor result and no implication that an app matches scientific lightning-imaging equipment.
Protocol
Six steps, recorded every time.
Freeze the setup
Record app build, iPhone model, iOS version, lens, capture format, trigger mode, sensitivity, analysis region, cooldown, burst and power state.
Describe the scene
Record illuminance or a repeatable light description, tripod or handheld use, distance to stimulus, background motion, temperature and thermal state.
Use a controlled stimulus
Prefer a repeatable indoor light pulse, moving target, fixed-level audio playback or measured device movement. Do not begin a safety test by standing in a thunderstorm.
Run enough trials
Use at least 30 planned events per configuration for an exploratory result. Keep warm-up trials separate and preserve misses instead of rerunning them silently.
Label each outcome
Record detection, capture request, completed save, usable frame, false positive, duplicate, readiness failure and any human intervention as separate fields.
Publish the denominator
Report raw counts with the number of planned events and observation time. Include the CSV, excluded trials and exact reason for every exclusion.
Measurements
What the final report should expose.
A result without a denominator, device or configuration is a product anecdote, not a reproducible measurement.
| Metric | Calculation | Why it matters |
|---|---|---|
| Detection rate | Detected planned events ÷ all planned events | Measures the trigger model before camera-pipeline failures. |
| Capture completion rate | Saved captures ÷ detected planned events | Shows whether detection became a file. |
| Usable-frame rate | Frames containing the intended moment ÷ all planned events | Captures the result a photographer actually cares about. |
| False-positive rate | Unplanned triggers ÷ observation time | Allows comparison across sessions of different length. |
| End-to-end latency | Stimulus timestamp to exposure or saved-frame timestamp | Must state the clock, recording method and uncertainty. |
| Readiness failures | Count by reason and camera state | Separates app detection from AVFoundation readiness. |
Suggested matrix
Change one important variable at a time.
| Trigger | Controlled stimulus | Minimum conditions to disclose |
|---|---|---|
| Lightning / brightness | Repeatable short light pulse outside and inside the selected analysis region | Pulse duration, relative brightness, ambient level, region and lens |
| Visual motion | Target moving across a marked path at repeatable speed and size | Direction, speed, subject size, background motion and distance |
| Sound | Fixed audio sample played at a measured distance and safe volume | Sound level if available, microphone orientation, ambient noise and keyword use |
| Device motion | Repeatable tilt, shake or impact using a marked movement range | Mount, movement amplitude, duration and device orientation |
| Stable scene | Tripod settling after a defined disturbance | Support, stabilization, settling threshold, wind and surface vibration |
Safety before footage
Do not field-test lightning from an unsafe position.
The National Weather Service states that there is no safe place outside when thunderstorms are in the area. Controlled indoor stimuli should be used for repeatability; any real-weather observation belongs inside a safe building or hard-topped vehicle and must follow local safety guidance.
Primary context
Sources and limits.
- Apple: AVCapturePhotoOutputReadinessCoordinator — camera readiness is a state to coordinate, not something a trigger can assume.
- Geophysical Research Letters: high-speed lightning observation — useful scientific context for lightning imaging, not validation of HyperCam or any consumer app.
- US National Weather Service: Lightning Safety and CDC safety guidance — safety instructions take priority over photography.
- HighRoad editorial policy — explains repository facts, primary sources, inference labels, corrections and comparison rules.
Independent testing welcome
Publish the misses too.
Reviewers may use or adapt this protocol without promising a favourable result. If you publish a dataset, link the configuration, raw counts and exclusions so another person can repeat the work.