I tried making artificial sunlight at home

Original Article ↗ Hacker News Discussion ↗

Use cases, mood, and everyday lighting

  • Many readers in dark climates relate; some report big mood improvements from bright “SAD” lights, sunrise alarm lamps, or adding strong lamps to otherwise dim “depression cave” apartments.
  • Practical issues: glare if the bright source is in the field of view, risk of overheating nearby plants, and aesthetics (very bright light reveals dust and grime, can feel clinical).
  • Windowless or underground rooms are a strong motivation, though some worry that realistic artificial sunlight could normalize dystopian housing.

Optical design and realism

  • Project is praised for compactness and clear documentation; comparisons drawn to the larger DIY Perks build and commercial systems like CoeLux.
  • Main realism gap discussed: getting light that appears to come from an angled, distant sun and casting correct shadows. Reflective/parabolic designs (e.g., satellite dishes) are better at making near-parallel rays but are bulky.
  • Ideas floated: moving the light on a track to simulate solar motion; hexagonal or Fresnel lenses; using commercial brightness-enhancement films.

Spectrum, health, and “true” sunlight

  • Extensive debate about spectra: high CRI (95+) is appreciated, but several note typical white LEDs lack deep red and near‑IR and have no UV, so they’re not truly sunlike.
  • Some argue NIR/IR are important for physiology; others say IR and UV are better supplied by separate heaters or UV fixtures due to safety and energy regulations.
  • A commercial skylight maker emphasizes “melanopic lux” (around 490 nm blue) as key for circadian and SAD effects, and describes multichip LED mixing to shape spectra.
  • Dynamic color temperature over the day is a highly desired feature to avoid evening blue light and support sleep.

Commercial products, cost, and access

  • High-end skylight systems exist, targeting architecture and luxury/underground projects; they focus on seamless sky appearance, collimation, and circadian metrics but are expensive and sold via agents.
  • Commenters express frustration with “contact us” pricing and wish for direct purchase options even at high price points.

Electronics, manufacturing, and measurement

  • Readers suggest PCB ground planes, thermal improvements, and caution against paralleling PSUs without careful load sharing.
  • The accessibility of services like JLCPCB for PCBs, custom lenses, and CNC is seen as a major enabler of such hobby projects.
  • Several recommend lux meters and affordable spectrometers; CRI is criticized as insufficient, with calls for full spectral plots and better metrics.