Use iPhone's camera as a lux meter
Details
- External ID
- 49139252
- Source
- HN
- Company
- —
- Product
- Use iPhone's camera as a lux meter
- Website domain
- impulsearc.com
- Launched
- Aug. 1, 2026
- Cohort
- —
- Upvotes
- 5
- Upvotes percentile
- 0.12634408602150538
- Tags
- —
- Fetched at
- Sept. 10, 2026, 5:32 a.m.
- Updated at
- Sept. 10, 2026, 5:32 a.m.
Description
After suffering one too many times from bad jet lag, I read a bunch of circadian rhythm papers and developed a simple app to help fight jet lag. I knew that avoiding devices at night was helpful, but it turns out that getting the right light at specific times of day can help not just with jet lag but overall sleep and well being.How it works: you give the app your sleep goal, and then it coaches you by estimating current melanopic light exposure from the iPhone's camera. I validated this against an $1800 lab-grade light meter and was surprised to find it is absolutely close enough for these purposes. (Note: I'm NOT a physicist or circadian rhythm researcher, so I'm grateful for any feedback.)If you feel like your sleep schedule could be more dependable or if you suffer from jet lag, you might enjoy this app!
Enrichment
- Theme
- sleep, wake, and clock utilities
- Vertical
- Horizontal
- Function
- Hardware & robotics
- Audience
- Prosumer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- iphone camera lux meter
- Manually corrected
- False
Could you build this?
Partial While an iOS app with camera preview and sleep-schedule recommendations is easy to assemble, converting raw RGB camera sensor readings into accurate photopic lux and circadian melanopic lux requires optical calibration across diverse phone hardware.
What it would actually take: A native iOS app (Swift/AVFoundation) that extracts raw exposure metrics (aperture, shutter speed, ISO) from the camera sensor and applies color science transforms to estimate illuminance. The hard part is building spectral sensitivity calibration tables to approximate melanopic daylight equivalent (melanopic lux) from consumer Bayer filters across varying indoor light sources. This demands photobiology modeling and optical hardware calibration expertise.
Discussion
No comments on this launch.
Competitors
Other products that read as similar to this one — 203 launches clear the similarity bar, closest 8 shown.
Attention rank: #191 of 204 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 256 days after the earliest competitor.
- Sleep Diary · ph · 2026-09-16 · 1 upvotes · similarity 0.50
- TimeCam · ph · 2026-09-28 · 1 upvotes · similarity 0.50
- Rano · ph · 2026-09-30 · 2 upvotes · similarity 0.49
- A bedside camera detects REM sleep and agrees with a clinical EEG · hn · 2026-07-05 · 10 upvotes · similarity 0.48
- Circadia — Arrivez reposé, pas épuisé · ph · 2026-09-09 · 1 upvotes · similarity 0.48
- DayZen: Visual day planner for ADHD brains · hn · 2026-01-24 · 17 upvotes · similarity 0.48
- UltraAlarm: Get Up Alarm Clock App · ph · 2026-09-12 · 1 upvotes · similarity 0.43
- Yawn Time · ph · 2026-09-27 · 2 upvotes · similarity 0.43
Other launches for this product
- No other launches for this product.
Same idea, different domain
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