Funny how LED technology & output has increased so much in one year but...

sfca · Mar 20, 2010

From ~ 2009 - 2010

For the mass-manufactured 2XCR123-type lights

Should have been:
225 lumens. 240 lumens. 250 lumens. 300 lumens. 380 lumens 400 lumens. 450 lumens.

Instead:
225 lumens. 240 lumens. 250 lumens. 230 OTF lumens. 300 OTF lumens. 350 OTF lumens.

One of those idiosyncrasies when I see it pushing "500 lumens" (like the 1.5A XP-G Thrunite drop-in at the marketplace) I'm like :huh:

. But when it's "350 OTF lumens" I'm like.. cool.

Just an observation.

choombak · Mar 21, 2010

Remember microprocessors?

-Amarendra

McAllan · Mar 21, 2010

After having been quite impresses with my TK40 I'm now looking forward to a AA based light with SST-90 emitter.

Or even better. Cree wakes up and make their version of a monster emitter. I believe they have have capability to make it even more efficient.
But as I recall increase in efficiency is on a decline. The remaining percents of "lost" power are getting harder and harder to convert to light. They might seem to have gotten overall much brighter but the way they've achieved that is by making the die larger. And since efficiency is higher at lower levels pr. surface the overall efficiency is higher. But at cost of more difficult throw since a larger area is emitting light.

divine · Mar 22, 2010

What's the difference between 450 lumens and 350 OTF lumens? :shrug:

Stress_Test · Mar 22, 2010

Yeah, I have to keep reminding myself that it takes a major jump in lumen output to create an impressive difference.

I hate spending the money on an upgrade and then comparing to another light and thinking "ummmm yeah it's a little brighter".

My current plan is to not make any light purchases till at least we hit the time change again in November; by that time hopefully there'll be some stuff out there that will be a real "wow" upgrade and not just an "ehhh".

(Waiting on the neutral XPG R4/5 driven at 1.5 amps!!

)

csshih · Mar 22, 2010

McAllan said:
After having been quite impresses with my TK40 I'm now looking forward to a AA based light with SST-90 emitter.

oh heck no!
we have enough problems with the battery setup in the tk40 (per 4sevens) with "normal" people. how many AAs will the sst-90 version need? sst-50 should be the highest power led in there

saabgoblin · Mar 24, 2010

Upset or disappointed with the changes in one year! :ohgeez:

Personally, I can't even keep up with the changes and I have been holding off on buying the newest lights because as soon as I buy something, it will already be outdated technologically speaking. Considering the fact that I am an old incan hound, I am blown away at the output created by the luxeon III, the SSCp4's, and the newer cree leds and anything more than those outputs(80+ Surefire Lumens) are icing on the cake as far as I can see at least for 95% of my needs. I am sure that there are professionals whose life depends on massive amounts of light but for most part, I can do just fine on 80+OTF depending on beam characteristics. I guess that we are just becoming conditioned to expect major leaps in technology every few months based on the technology boom in computing.

Maybe I don't hang out with enough Flashaholics because most people that I run into are blown away with my stock lights from three years ago, and even a stock E1e will turn most any head in a crowd. Unless I was in law enforcement and or part of a search and rescue team, I could barely find an actual use for 350-OTF Lumens other than just seeing what 350 could do in a situation. I'll take the 350 but in my eyes, "we have come a long way baby" to borrow a phrase from the 1970's damn, I am getting old.:shakehead

McAllan · Mar 24, 2010

csshih said:
oh heck no!
we have enough problems with the battery setup in the tk40 (per 4sevens) with "normal" people. how many AAs will the sst-90 version need? sst-50 should be the highest power led in there

I don't use alkalines. 8 NiMH should be enough to drive to full power. But who says it should be given full 9 amps ?
LEDs are more efficient at lower levels so just driving it with half would still be quite nice and output would in fact be a little more than half with full power.

Or make a 4 D in the style (but not materials!) of the old plastic 2x2D configuration with a large reflector. That would be a nice thrower. Still miss the incan I/my dad had years ago. What a nice thrower that even put M*gs to shame. And a handle to make carrying it comfortable.

photonwave · Mar 24, 2010

I am still waiting in massive increases in output. Theoretical maximum lux/w is around 680.

Of course, i can only imagine what sort of heatsink we'd need to keep that within thermal tolerance ranges.

hoongern · Mar 24, 2010

McAllan said:
I don't use alkalines. 8 NiMH should be enough to drive to full power. But who says it should be given full 9 amps ?
LEDs are more efficient at lower levels so just driving it with half would still be quite nice and output would in fact be a little more than half with full power.

Or make a 4 D in the style (but not materials!) of the old plastic 2x2D configuration with a large reflector. That would be a nice thrower. Still miss the incan I/my dad had years ago. What a nice thrower that even put M*gs to shame. And a handle to make carrying it comfortable.

I think it was not a reference to alkaline/ni-mh but the number of cells needed - and dangers of reversed polarity.

photonwave said:
I am still waiting in massive increases in output. Theoretical maximum lux/w is around 680.

Of course, i can only imagine what sort of heatsink we'd need to keep that within thermal tolerance ranges.

I think you probably meant lumens/watt rather than lux/w

And a good article: http://en.wikipedia.org/wiki/Luminous_efficacy

Juggernaut · Mar 24, 2010

photonwave said:
I am still waiting in massive increases in output. Theoretical maximum lux/w is around 680.

Of course, i can only imagine what sort of heatsink we'd need to keep that within thermal tolerance ranges.

? The other way around…. As emitters get more effective they need less heat sinking AKA: say you drive a P4 at 1A and a S2 at 1A. The P4 makes *235 lumens and the S2 makes 400 Lumens. The S2 is going to actually make less heat because it turns more of that power into light and not into heat, in fact it will make almost half as much heat with almost double the output. You only get more heat with less efficient dies or simply more of them. Such as the SST-90.

Note most of those facts might be bit off, but the point is in there.

photonwave · Mar 24, 2010

hoongern said:
I think you probably meant lumens/watt rather than lux/w

And a good article: http://en.wikipedia.org/wiki/Luminous_efficacy

The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. IOW - it's basically the same thing but lux includes area of a surface being illuminated whereas lumens is typically represented at the surface of the bulb.

http://en.wikipedia.org/wiki/Luminous_emittance

Either one is still an SI recognized unit and both are measured as lux or lumens per square meter. Lumens only deals with light humans are sensitive to, weighted at 500nm. Lux is for all other light emissions NOT involving the typical visual lighting industry - in my part of the lighting industry, we don't use ANY of those terms, we go by umol/m^2/s-1.

photonwave · Mar 24, 2010

Juggernaut said:
? The other way around…. As emitters get more effective they need less heat sinking AKA: say you drive a P4 at 1A and a S2 at 1A. The P4 makes *235 lumens and the S2 makes 400 Lumens. The S2 is going to actually make less heat because it turns more of that power into light and not into heat, in fact it will make almost half as much heat with almost double the output. You only get more heat with less efficient dies or simply more of them. Such as the SST-90.

Note most of those facts might be bit off, but the point is in there.

Second law of Thermodynamics applies, and you have the fact that such a tiny body emitting such a high output level of photons is going to create a lot of heat. In fact, such a high photon output would be so energetic as to be 'hot' even a small distance away from the emitter.

Tested and tried through several LED tube applications. The more efficient the LED, the more heatsink we needed because the emitter got that hot.

That 10w LED tube I have (part of it is my avatar picture) required every bit of that aluminum heatsink to maintain a stable thermal profile, and even then I still had to pop vent holes in the end caps because that much heat is generated (compared with my lite-brite tail-thru LED bar which needs practically no thermal cooling solution except exposure to air) and created cap-blowing pressure inside the tube.

blasterman · Mar 24, 2010

The more efficient the LED, the more heatsink we needed because the emitter got that hot.

If you're dealing with a current regulated circuit how can that happen? Energy in = energy out. Older, less efficient emitters will tend to get flaky on a fixed voltage circuit as they get hotter, but current regulation should keep this in check. (??)

Also, 10w of power should be easy to handle from a themal perspective, especially with 1watt emitters.

I'm not getting this vibe about radically more efficient emitters. The XPG made more improvements in terms of it's thermal / current density envelope, correct?

hoongern · Mar 24, 2010

photonwave said:
The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. IOW - it's basically the same thing but lux includes area of a surface being illuminated whereas lumens is typically represented at the surface of the bulb.

http://en.wikipedia.org/wiki/Luminous_emittance

Either one is still an SI recognized unit and both are measured as lux or lumens per square meter. Lumens only deals with light humans are sensitive to, weighted at 500nm. Lux is for all other light emissions NOT involving the typical visual lighting industry - in my part of the lighting industry, we don't use ANY of those terms, we go by umol/m^2/s-1.

Yes, I am aware of the differences between lux and lumens. But if you want to use lux, then you'd have to say the theoretical maximum is about 680lux*m^2/W. Without the square meter part, then it's incomplete. Please correct me if I'm wrong.

HKJ · Mar 25, 2010

photonwave said:
Second law of Thermodynamics applies, and you have the fact that such a tiny body emitting such a high output level of photons is going to create a lot of heat. In fact, such a high photon output would be so energetic as to be 'hot' even a small distance away from the emitter.

You are confusing a few terms.
A 10 w led will make more heat than a 3 watt led with the same efficiency.

But an old 3 watt led will make more heat than a new 3 watt led with higher efficiency.

If you get a led with 100% efficiency, it will not generate any heat.

The light from the led will be converted to heat when absorbed, that can be on a 80% reflectance reflector, where the last 20% is converted to heat (the same goes for the front glass, it also absorbs some light and converts it to heat).

BlueMarble · Mar 25, 2010

saabgoblin said:
Upset or disappointed with the changes in one year!Personally, I can't even keep up with the changes and I have been holding off on buying the newest lights because as soon as I buy something, it will already be outdated technologically speaking. Considering the fact that I am an old incan hound, I am blown away at the output created by the luxeon III, the SSCp4's, and the newer cree leds and anything more than those outputs(80+ Surefire Lumens) are icing on the cake as far as I can see at least for 95% of my needs. I am sure that there are professionals whose life depends on massive amounts of light but for most part, I can do just fine on 80+OTF depending on beam characteristics. I guess that we are just becoming conditioned to expect major leaps in technology every few months based on the technology boom in computing.

Maybe I don't hang out with enough Flashaholics because most people that I run into are blown away with my stock lights from three years ago, and even a stock E1e will turn most any head in a crowd. Unless I was in law enforcement and or part of a search and rescue team, I could barely find an actual use for 350-OTF Lumens other than just seeing what 350 could do in a situation. I'll take the 350 but in my eyes, "we have come a long way baby" to borrow a phrase from the 1970's damn, I am getting old.:shakehead

Great post! I enjoyed reading it. Thanks!

McAllan · Mar 25, 2010

hoongern said:
I think it was not a reference to alkaline/ni-mh but the number of cells needed - and dangers of reversed polarity.

Not remotely as dangerous as mistreating LiIons. If people can't handle the cells properly whether there's 2 or 8 or any number for that matter then they would be better of with M*gLites. Perhaps best the rechargeable one - after insertion no cells to handle. Of course at the expense of lost flexibility and when it runs out you have to recharge while us preferring loose cells can just reload and we're good to go again.

LedTed · Mar 25, 2010

So all,

What are we, as a group, calling the brightness measurements of LED flashlights? I'm NOT talking about NIST or ISO testing methods.

I mean to ask; which is the most used manufacturer made-up measurement term: Beam Candlepower, Emitter Strength - Lux, Out the Front (OtF) Lumens, Torch Lumens, something else?

I'd like to write a review and want to use a term that the most of us are familiar with.

csshih · Mar 26, 2010

just plain old lumens.

Funny how LED technology & output has increased so much in one year but...

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