Magnitude (light intensity)

Firefly

Candle flame

Electric arc

Luxor Sky Beam

Sun

This is a compilation of luminous intensities of various orders of magnitude for comparison purposes. The information is often to be understood as “typical values”; the converted values ​​are rounded. It should be noted that bundled light sources - in the solid angle of the light beam - can achieve much greater light intensities than sources that radiate light in all directions.

The basic unit for luminous intensity in the international system of units is 1  candela ( unit symbol cd ).

See also : Unit prefixes  and Scientific notation

Up to a candela

• 2.4 x 10 ^-16 cd - a light source, a photon of frequency 5.4 × 10 ¹⁴ Hz (green yellow light) per second and steradian emits
• 3 · 10 ⁻⁷ cd = 300 ncd - dial of a clock with luminous paint in the dark
• 1 · 10 ⁻⁵ cd = 10 µcd - Superluminova watch dials in the dark
• 1 · 10 ⁻² cd = 10 mcd - fireflies
• 1 · 10 ⁻² - 5 · 10 ⁻² cd = 10 to 50 mcd - normal light emitting diodes
• 1 · 10 ⁰ cd = 1 cd - candle flame

Between 1 and 1000 candela

• 1 · 10 ¹ cd = 10 cd - obstacle lighting at aviation obstacles , minimum value
• 5.8 x 10 ¹ cd = 58 cd - incandescent lamp , 60 W
• up to 6 · 10 ¹ cd = up to 60 cd - very bright light- emitting diodes , so-called super emitters
• 1 · 10 ² cd = 100 cd - mandatory bicycle lighting in Austria
• 1.1 · 10 ² cd = 110 cd - incandescent lamp , 100 W.
• 1.8 · 10 ² cd = 180 cd - fluorescent tube , 40 W
• 4 · 10 ² cd = 400 cd - daytime running lights according to ECE regulation No. 87, minimum value
• 4.3 · 10 ² cd = 430 cd - mercury vapor lamp , 125 W.
• 8 · 10 ² cd = 800 cd - electric arc , 250 W

Between 1000 and 10 ¹⁵ candelas

• 1.6 · 10 ³ cd = 1.6 kcd - arc lamp
• 2 · 10 ³ cd = 2 kcd - hazard lights at aviation obstacles , minimum value
• 1 · 10 ⁴ cd = 10 kcd - mercury vapor lamp, 2000 W
• 1.5 · 10 ⁴ cd = 15 kcd - distress signal means hand torch red
• 4 · 10 ⁴ cd - 7 · 10 ⁴ cd = 40 to 70 kcd - high beam on high- speed trains
• 8 · 10 ⁴ cd = 80 kcd - distress signal means parachute signal cartridge red
• 2.25 · 10 ⁵ cd = 225 kcd - high beam on vehicles in traffic (maximum permissible value of the sum of all headlights)
• 5 · 10 ⁵ cd = 500 kcd - beacon for seafaring
• 2 · 10 ⁶ cd = 2 Mcd - beacon for aviation
• 4.5 · 10 ⁶ cd = 4.5 Mcd - lighthouse camping
• 6-8 · 10 ⁶ cd = 6-8 Mcd - stun grenade
• 3.5 · 10 ⁷ cd = 35 Mcd - Helgoland lighthouse
• 2.7 · 10 ⁹ cd = 2.7 Gcd - Turbinlite search light on some US American Douglas A-20s
• 4 · 10 ¹⁰ cd = 40 Gcd - Luxor Sky Beam of the Luxor Hotel and Casino

More than 10 ¹⁵ candelas (astronomical)

• 3 · 10 ¹⁶ cd - moon , reflection in the direction of the sun
• 8 · 10 ¹⁸ cd - Brown dwarf ε Indi Ba
• 4 · 10 ²² cd - Red Dwarf Wolf 359
• 3 · 10 ²⁷ cd - sun
• 1 · 10 ³¹ cd - Rigel
• 3 · 10 ³⁵ cd - Supernova 1987A
• 4 · 10 ³⁶ cd - Supernova S Andromedae
• 4 · 10 ³⁷ cd - Milky Way
• 8 · 10 ³⁹ cd - Quasar 3C 273
• 4 · 10 ⁴³ cd - brightest Hypernova GRB 080319B observed so far (in the direction of the jets)