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One field of our ongoing research is illumination, specifically passive, and emergency light solutions.

GITD vs Chemlight vs Tritium

Mini-chemlight, GITD tab, or tritium vial; which one and when? Depending on the application, all three have advantages and disadvantages.

Wndsn: GITD vs Chemlight vs Tritium

Brightness over time

Given comparable form factors:

  • First 10 minutes after exposure: Mini-chemlight = GITD > Tritium
  • Beyond 10-15 minutes after exposure: Mini-chemlight > Tritium > GITD
  • Beyond 4-6 hours after activation: Tritium >= Mini-chemlight >= GITD

For rapid changes from light to dark GITD is brighter than mini-chemlights and Tritium, for practically infinite marking in continuous low-light settings, Tritium is superior; and for fast and acute ambient illumination, chemlight is preferable.


10 years > 4 hours > 10 minutes. 

  • GITD: 10 usable minutes, starting immediately after charging.
  • Mini-chemlight: 4-6 hours, starting at will.
  • Tritium: 10 years half-life, if it's on, it's on.

Supplies required

  • GITD: sunlight, UV-light, a 1000 lumen torch isn't enough.
  • Chemlight: consumables, the more the better.
  • Tritium: good as is.

Shielding and containment

  • GITD: no shielding needed, contain light in mylar pouches, etc.
  • Chemlight: prevent breaking prematurely or destruction by keeping within solid plastic tubes, etc.; contain light in mylar pouches, etc.
  • Tritium: prevent vials from breaking by using the obligatory cage-shaped holders, contain light in mylar pouches, etc. (Tritium emits enough light to shine through 500d Cordura)

As always, more area equals more light. Area makes a big difference, since everything about light is quadratic.[1] If you need more light, bring a bigger or more light sources, no matter which of the above.

See also:


  1. Wndsn: Measuring Light 

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