1 Watt v.s. 3 Watt question?

In general, given the same power source, how much more light should a 3w LED produce over a 1W LED. To make the question easier, assume as many variables as possible are the same - and discounting the luxeon lottery.

Looking at flashlightreview.com throw/output chart, it doesn't appear that much percentage wise.

Hello YukonJack

IMO your question should be: "Which bin-code is brighter?"

The 1 Watter goes to r-bin but I think, the frontier is not really definated.

Bin Codes Explained

Best regards

_____
Tom

An S bin at 350mA (Lux I) generally outperforms a T bin at 350mA. At 700mA, the T bin (Lux III) should outperform the S bin (S bin is overdriven substantially with a shortened lifespan).

I understand difference in bin codes - at least in dealing with the same wattage. Manytimes, there is simply no way of knowing the bin number beforehand. However, my question remains the same, and I'm sure many folks have the same question.

Simply put, I suspect most of the buying public expect a 3W LED light to be quite a bit brighter than a 1W LED light given the same power source. In fact, most folks guess a 3W light is 3 times as bright as a 1W and will run only 1/3 rd as long.

Look here for some good experimental data comparing 1 watt parts against 3 watt parts (and a few 5 watters, too).

http://candlepowerforums.com/vb/showthread.php?t=115323

What I gathered from this was a 1 watt R bin nearly equals a 3 watt U bin when both are driven at the same level of power. That means the R bin probably meets or exceeds a typical T bin, again assuming you drive them both the same.

R bin 1 watt parts seem to be reasonably available. You can even find an occasional S bin 1 watt. I would consider the T bin 3 watt to be very readily available. It seems more difficult to find a U bin.

I'll leave it up to you to decide whether overdriving a 1 watt part to the 3 watt levels is hazardous to the lifespan of the emitter. Another consideration is that tint shift comes into play, and neither an overdriven 1 watt nor an underdriven 3 watt is guaranteed to be in its rated color bin.

While most 3 watt lights put out more lumens than 1 watt lights, and some put out 3 x as many lumens, it generally takes doubling the number of lumens to make a noticable difference to the eye. The eye is not very sensitive to brightness differences. Most 3 watt lights seem "somewhat" brighter than 1 watt lights, but most are not "lots brighter" to the eye.

Holland

One of my lights with the best throw is the Streamlight TL-2 LED (new version), and I understand it is just a LuxI.

one f stop difference on a photographic lightmeter.

Ty_Bower said:

...
I'll leave it up to you to decide whether overdriving a 1 watt part to the 3 watt levels is hazardous to the lifespan of the emitter.....

Click to expand...

I think there is an asumption here that there is an actual physical difference between the Lux I and the Lux III emitter. There is quite a bit of speculation on CPF that the bare emitter of a S Bin LuxI and a T Bin Lux III are actualy the SAME thing, but with a different marketing spin.

If the emitter is mounted on a star board then the Lux III board is thicker and there seems to be a better thermal path to the board. This allows a higher drive level and therefore the higher wattage rating of the LuxIII part.

In conclusion its not about the emitter its about how it is driven and how good the heatsink is.

stjohnh said:

While most 3 watt lights put out more lumens than 1 watt lights, and some put out 3 x as many lumens, it generally takes doubling the number of lumens to make a noticable difference to the eye. The eye is not very sensitive to brightness differences. Most 3 watt lights seem "somewhat" brighter than 1 watt lights, but most are not "lots brighter" to the eye.

Holland

Click to expand...

This is totally true and very important for those considering LuxIII mods to many of these single AA lights. When I did the same to a fenix using flupic, the diffence is certainly noticable but not dramatic. It will be more impressive to folks, but then using the brightness of a pocket flashlight to impress people might say a little more about other things than one would want.....

In terms of an excellent runtime/brightness compromise , an efficient 1 watt emitter with 2 level dimming would likely be the best combo in a AA light .

I use these rule of thumb numbers for stock lights.
3AA/D or 2CR123 lights can provide 700mA (3watts) giving 75 lumens.
3AAA lights due to the low power output of the batteries manage only 40 lumens.
1AA, 2AA or 1CR123 lights ususlly have a 1 or 1-1/2 watt boost circuit giving 25-30 lumens.

In 1AA, 2AA or 1CR123 lights the brightness is dependant more on the boost circuit than the LED.
An extreme case is the Peak Pacific 3W which is driven in the ~70mA (1/4watt) range giving ~10 lumens.
On the other hand, Millermods upgrades for the L1P and others for the Q3 provide a lot more light without the need to swap the LED. Of course CPFers will swap the LED as well especially if they have a super efficient U-bin lux lying around.