BrightNorm posted this the other day
brightNorm posted this the other day;
Space Needle II faces down incandescent wolf pack
Initial comments and observations
The Space Needle II, mounted in a 2C Maglite, is powered by three 123 lithium cells and substitutes a 5W Luxeon for the standard incandescent bulb. It display's Charlie Wong's usual superb job of design and execution. The focusable Luxeon is mounted on a round plate precisely placed within the reflector's center aperture. The batteries are securely held in a thick rubber-like tube which prevents any rattle, even when the light is vigorously shaken. As is usual with Charlie's mods, the Luxeon has been carefully selected for quality and brightness. The light is "direct drive".
IMPRESSIONS, TESTING MODALITIES AND COMPARISON TESTS
Both the "whiteness" and intense brightness of the Space Needle II were unexpected and impressive. When projected upon a light surface the color can be described as a brilliant, cold, moon-like white. However, when looking (obliquely) into the beam, the similarity to an HID beam is striking.
Beam analysis
Beam analysis will concentrate on size, intensity and throw as determined by indoor and outdoor testing. Run tests were not conducted since runtime was not a design consideration of this light. The first series of indoor tests measures the SN II's hotspot diameter compared with that of nine incandescent lights: SF D3/SRTH/N2, SF D3/P91, Tigerlight, MagCharger with "bright" standard bulb, UltraStinger, Stinger HP, PolyStinger, TACM III and Pelican M6.
Hotspots
Hotspot diameter, along with wattage, reflector characteristics and lamp efficiency correlates with intensity and throw. However, the distribution of total energy between the hotspot and the surrounding beam sometimes accounts for seemingly contradictory results from one light to the next. The D3/SRTH, PolyStinger, D3 P91, and Pelican M6 have fully textured reflectors which project a relatively amorphous beam making hotspot measurement difficult. This was somewhat less problematic with the D3/SRTH since its tight focus was more clearly delineated and thus easier to measure. The D3/P91's beam was so broad and smoothly graduated that an accurate hotspot measurement was not possible. No attempt is made here to measure beam "brightness" per se, as major reviewers have developed sophisticated techniques for this purpose.
Several of the tested lights had what can be described as a "hotspot nucleus" or a "hotspot within the hotspot", which is a smaller, brighter spot inside the regular hotspot. The lights exhibiting this were the MagCharger, UltraStinger, and Stinger HP. It was this "nucleus" that enabled the MagCharger to outthrow other lights in a previous test.
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INDOOR TEST #1: Hotspot diameter
Smallest Hotspot diameter at 24'
Space Needle II: 37"
D3/P91: 30"-50"*
D3/SRTH/N2: 21"
Tigerlight: 20"
Pelican M6: 19"
Polystinger: 19"
MagCharger: 15"
UltraStinger: 15"
TACM III: 15"
Stinger HP: 10"
The second indoor test series compared the total output of these lights and was performed in two stages. The first utilized the Meterman LM631 light meter. The second relied on subjective impressions obtained through several methods.
Metered comparisons of "total output"
These tests do not measure beam "brightness"
To repeat: no attempt is made here to measure beam "brightness" per se, as major reviewers have developed sophisticated techniques for this purpose. These tests aim to determine a light's total output by measuring INDIRECT brightness only, achieved by shining each light at a precise point on the ceiling from a specific position on a table. These results should proportionately correlate very roughly with rated lumens, and suggest a lumen rating for unrated lights. Please note that these tests are for comparative rankings only and are not definitive measurements of light energy. Thus, numerical values should be considered as abstract units only.
INDOOR TEST #2 (METERED) "TOTAL LIGHT OUTPUT"
D3/P91: 27.9
Tigerlight: 26.9
Space N. II: 24.6
Ultra Stngr: 23.2
MagChrger: 22.7
D3/SRTH/N2: 22.2
Pelican M6: 19
TACM III: 18.3
PolyStinger: 18.2
Stinger HP: 18.2
There is some question as to whether the P91's wide beam spill was reflected more powerfully into the Lux meter's sensor, perhaps by adjacent walls, than the TigerLight's. The identical results for the PolyStinger and Stinger HP help to validate the testing procedure, since despite having different beams, the two lights have identical wattage and output.
Subjective tests for total output
These evolved out of a curiosity to see how closely "eyeball" tests correlated with instrumented tests. Methodology combined several techniques including an eyes-closed "substitution" test, an eyes-open reflection test and other attempts to measure the total amount of light projected within a room. Each of the incandescent lights were compared in turn with the SpaceNeedle II.
This list shows the subjective impression of relative brightness grouped by those lights which seemed brighter than the Space Needle and those which seemed "dimmer".
Brighter (appearing) light is in bold type
SN II D3/P91
SN II Tigerlight
SN II Magcharger
SN II UltraStinger
SN II TACM III
SN II Stinger HP
SN II D3+SRTH+N2
SN II Pelican M6
SN II Polystinger
The subjective list matches the instrumented list except for the MagCharger which measured lower than the Space Needle.
OUTDOOR TESTING
Methodology
As in the past, due to crowded urban conditions I have developed my so-called "Vertical throw tests". I pace off a specific distance from a building as measured by pedometer, with compensation factored in for turns and corners. Then I select an aim point on a tall building and count the number of floors, conservatively assigning 10 feet per floor. I may sometime reverse this procedure, counting floors first. When I have my distance and height, I use Pythagoras to derive the hypotenuse, which equals the total distance of the test. Accuracy can't be exact but is pretty close because I measure very carefully. I try to enlist the services of at least one witness, usually more. They are non-Flashaholic friends, colleagues and my generally tolerant girlfriend. I have added the SureFire M6 to the following tests.
VERTICAL THROW TEST #1
Tested: SPACE NEEDLE II, SUREFIRE M6, TIGERLIGHT
Height: 140' (14 floors)
Distance: 40'
Total distance: 146'
When tested by itself the SN II easily illuminated a broad area of the 14th floor, appearing very bright with a subtly blue-tinted white light that was strongly reminiscent of automobile HID headlights in color. When compared with the Tigerlight however, it was clear that the Tigerlight's beam was considerably smaller in diameter as well as significantly brighter. The Space Needle was then tested directly against the SureFire M6. The TigerLight was excluded from this test since comparisons with the M6 are well covered in other reviews. See:
url=http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=UBB1&Number=34870&page=&view=&sb=5&o=&fpart=1&vc=1]NEW TEST RESULTS FOR TIGERLIGHT AND M6[/url]
The M6 brilliantly illuminated a large portion of both the 13th and 14th floors, and overwhelmed the beam from the Space Needle. It should be remembered however that the M6 has similarly overwhelmed the beams from many powerful lights. (reference previous thread)
VERTICAL THROW TEST #2
Tested: SPACE NEEDLE II, SUREFIRE M6, TIGERLIGHT
Height: 140' (14 floors)
Distance: 260'
Total distance: 295'
The Space Needle comfortably reached the target, but with a much broader beam that had paled considerably from the previous test. The impression was of a "wash" of light rather than a "beam" of light. The M6 retained considerable power and illuminated virtually the entire top of the building with a diminished but still remarkably potent beam.
Additional observations and comments
Reflector
When I first received the space needle I saw what appeared to be an unusually brilliantly polished reflector, much "shinier" than that of the MagCharger. Then I recalled that Charlie had installed a UCL lens on the light. It was the true transparency of the lens that created the illusion of a brighter reflector, and allowed the passage of approximately 8% more light.
Wavelength
A question remains: how do the differing light wavelengths of the Space Needle II and its incandescent challengers affect subjective perception of brightness as well as metered "perception". Is it a factor?
Human brightness perception (apart from wavelength)
Humans can supposedly differentiate between hundreds of thousands of different colors, between many different odors, between the faces of hundreds if not thousands of other humans. Is there a similar sensitivity to nuances of brightness? The tests results are heartening by tentatively pointing in that direction.
Perceptual bias
I always knew which lights I was testing. This was unfortunate in terms of genuine objectivity which can only be achieved through well controlled double-blind tests.
Beam diameter
The SN II was at a powerful disadvantage in the throw tests because of its large beam diameter. The Mag reflector is a good one but does not permit the Luxeon to focus tightly without incurring the notorious "donut hole".
Technical Limits
LED manufacturers have demonstrated their ability to make increasingly brighter LEDS, but relatively low LED efficiency at higher power levels remains a serious problem. According to some estimates, efficiency of 30 lumens per watt will be achieved within a year, followed by 50-60 lumens per watt in four years.
Conclusions
Charlie Wong is among the vanguard of modders and creators who are pushing the envelope of LED capability. His Space Needle II, along with lights from other modders, points the way toward a future world of lighting dominated by the LED. At the same time, new incandescent technologies like Tungsten Lattice lighting are nipping at LED heels. The next few years promise to be exciting ones for the members of CPF.
Brightnorm
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