3 ms·

Wouldn’t get the same if not more of all the wavelengths by just sitting outside for 5 minutes? Is that maybe what you’ve been missing?

• lima 7y ago
  You're not missing anything, sufficiently bright natural sunlight would have the same effect.
  • manmal 7y ago
    No, radiation is not strong enough to have a significant effect, according to Prof Hamblin. Locations that are higher up (mountains) are better in that regard.