Kitchen Panda
Enlightened
I'm having a hard time interpreting beam shots. It seems to me that beam angle would be a good thing to know, and would give a numerical distinction between "throwy" and "floody" lights. Just to clarify the question in my mind, I tried some lights, estimated the diameter of the "hot spot" and calculated beam angles.
It's hard to estimate the hot spot size since I was eyeballing it; I should have picked the 10% of peak brightness contour, or something like that, to make it a scientific measure.
So, I would expect anything with a hot spot beam angle of much less than 10 degrees would be called a "throwy" light, and wider beam angles would be "flood". (The Maxabeam Web site shows what a 1 degree beam angle would look like.) The desk lamp is handy...it's hot spot is only a little more than one steradian, and it has almost no spill, so now I have a reference for what a steradian looks like.
The incandescent lights I have are very poor, but represent a lot of really crummy flashlights. The beam angle is probably not quite as tight as I report it because the little orange spot these make is hardly even circular. The #222 penlight is the oldest flashlight I own; it must be 40+ years old, and has consumed innumerable batteries and bulbs over that time.
The keychain button cell LEDs have no reflectors; it's just the LED dome concentrating the light. The Craftsman laser was what I was using to measure distance and then I thought "It's a light, isn't it?" Not very many lumens, but very throwy. What's 3 millwatts of red light in lumens?
The Mag-Lite was turned down to its narrowest beam; set on flood, the "donut" was taller than the wall I was aiming at 30 feet away. The TK70 hot spot was very broad and could be larger than what I measured.
I wish more beam shots were taken against a grid.
Bill
Light | Distance Inches | Spot Diameter Inches | Beam Angle Degrees | |
Ikea Jamso LED desk light | 29 | 32 | 57.8 | |
#222 Penlight 2AA | 30 | 12 | 22.6 | |
Photon Micro Light 5 mm LED | 30 | 11 | 20.8 | |
Illuminati CA1-AL | 31 | 9.5 | 17.4 | |
Battery Junction Keychain | 30 | 9 | 17.1 | |
Quark AA | 80.63 | 17 | 12.0 | |
Pelican L1 5 mm LED | 30 | 5 | 9.5 | |
Led Lenser 3AAA | 30 | 4.5 | 8.6 | |
TK70 | 365 | 32 | 5.0 | |
Mag LED 3D (tight) | 364 | 23 | 3.6 | |
2 for $6 Canadian Tire 2D incandescent | 88 | 4.5 | 2.9 | |
Craftsman Laser Distance Measure | 368 | 0.13 | 0.019 |
It's hard to estimate the hot spot size since I was eyeballing it; I should have picked the 10% of peak brightness contour, or something like that, to make it a scientific measure.
So, I would expect anything with a hot spot beam angle of much less than 10 degrees would be called a "throwy" light, and wider beam angles would be "flood". (The Maxabeam Web site shows what a 1 degree beam angle would look like.) The desk lamp is handy...it's hot spot is only a little more than one steradian, and it has almost no spill, so now I have a reference for what a steradian looks like.
The incandescent lights I have are very poor, but represent a lot of really crummy flashlights. The beam angle is probably not quite as tight as I report it because the little orange spot these make is hardly even circular. The #222 penlight is the oldest flashlight I own; it must be 40+ years old, and has consumed innumerable batteries and bulbs over that time.
The keychain button cell LEDs have no reflectors; it's just the LED dome concentrating the light. The Craftsman laser was what I was using to measure distance and then I thought "It's a light, isn't it?" Not very many lumens, but very throwy. What's 3 millwatts of red light in lumens?
The Mag-Lite was turned down to its narrowest beam; set on flood, the "donut" was taller than the wall I was aiming at 30 feet away. The TK70 hot spot was very broad and could be larger than what I measured.
I wish more beam shots were taken against a grid.
Bill