Fenix...Something I Didn't Expect

Confederate

Enlightened
Joined
Jun 22, 2006
Messages
360
I ordered a number of flashlights for my family, all Fenix, and when I got them last week, I packed them away and didn't think anymore about it. I live one state away from my parents and my sister, and me, not needing anything real fancy, I saw no need to replace my regular Fenix L2D. But with a fresh set of batteries, I was quite astounded by the difference between my L2D and a Q5 P3D...or perhaps I should say, I was astounded that it wasn't as different as I'd thought.

Going onto the back deck where it was very dark, I cycled through the various power levels of both lights. The P3D Q5 was noticeably brighter than the L2D on FULL THROTTLE, but not as different as I expected. Both lights tore through a respectable distance and lit up objects way up in the woods lot. But it wasn't the difference I was expecting. If both had been Q5s, I wouldn't have been disappointed. The extra voltage in the P3D would have accounted for the difference. But seeing that my L2D wasn't the Q5, I was...perplexed.

Turning both lights OFF, I turned the heads clockwise to enter the LOW modes. Hitting the switches, I noticed that my L2D now had a distinct edge in brightness over the P3D. Both were dim, as expected, but the Q5 P3D was noticeably dimmer.

The batteries in my L2D were NiMH AAs. The batteries in the P3D were new Duracell lithums. I wondered if perhaps a Q5 had found its way into the head of my L2D or, worse, whether the two P3Ds I had might be defective. Or...maybe I was defective. Maybe I overlooked something.

Having previously compared two P3Ds, a Q5 and the previous version, in a dark woods, I wasn't sufficiently impressed by the difference between the two, but that was months ago with other lights. I also recently picked up a couple of Nitecore D10s and was very happy with those, though I didn't expect much light from them (being single AA lights). In that case, I wasn't disappointed, but for these I was far more interested in the LOW modes than the HIGH. They put out respectable light, and both were consistent.

Anyway, getting back to the Fenix lights, any comments on what I may have been experiencing?
 

Gunner12

Flashaholic
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Dec 18, 2006
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Location
Bay Area, CA
The P3Ds have a lower low and medium mode and a higher turbo mode then the L2D/P2D. That is normal.

Remember that for our eyes to register one light as 2x brighter then another, the brighter light has have 4x the lumen figure.

The L2D-CE should seem 10-20% dimmer on turbo then the P3D-CE Q5.
 

Marduke

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Jun 19, 2007
Messages
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Location
Huntsville, AL
Two possible things are at play here.

1) The jump in brightness between the L2D CE and P3D Q5 on paper seem large, but in person to the human eye, it's not a large difference. It takes roughly twice the brightness for one light to look noticeably different from another (given similar beam patterns). Chuck it up to logarithmic perception of brightness by human eyes.

2) Depending on when you bought your L2D, it very well could be a Q bin. In fact, if it was a fairly recent purchase, it's likely a Q2-Q4 bin. The non-premium Fenix's are spec'd as P4 bins, but that's a minimum value. Now that the Cree X-lamp line is mature, they really don't make that many low bins. So although Fenix orders P4's or higher, they get mostly higher since that's what is being made.

BTW, the extra voltage of the P3D doesn't mean anything for brightness. LED's are generally regulated, and a circuit determines the voltage and current the LED is driven at, not the power source.
 

LEDninja

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Jun 15, 2005
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Hamilton Canada
L2D batteries are at 2.4V. Boost circuit brings it up to 3.6V.
P3D batteries are at 6V. Buck circuit brings it down to 3.6V.
While there are major differences in the battery voltage, the voltage at the LED is similar.

That being said there is usually a difference in amperage.
1AA/AAA boost circuits usually max out at 350 mA (there are some 500 mA drivers out there but they are not often used due to size, cost, inability to get rid of heat).
2AA boost circuits can double that to 700 mA.
2*lithium buck circuits have no problem running up to 1A or higher. The limiting factor is the ability to get rid of the heat produced. With a body smaller than the L2D, the P3D cannot get rid of the heat easily, so the instructions not to run in turbo for extended periods.

The official Fenix specs are
215 lumens for the P3D Q5
180 lumens for the L2D Q5
135 lumens for the L2D CE
P3D Q5 vs L2D Q5 - 215 lumens/180 lumens =1.19X brighter.
P3D Q5 vs L2D CE - 215 lumens/135 lumens =1.59X brighter.

As others have said you need 2X brightness to notice a significant difference in brightness. The P3D Q5 falls short of that against all models of the L2D.
 

EugeneJohn

Newly Enlightened
Joined
Jul 15, 2007
Messages
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Location
SoKy
Turning both lights OFF, I turned the heads clockwise to enter the LOW modes. Hitting the switches, I noticed that my L2D now had a distinct edge in brightness over the P3D. Both were dim, as expected, but the Q5 P3D was noticeably dimmer

This is one of the things that sold me on the P3D over the L2D... the lower low.

In an unlit house at night the low mode of the P3D is still pretty bright and the L2D would be brighter still.

Sometimes I want just the minimum amount of light that fits the situation. That desire for a low, low is one of the reasons why my EX10 has replaced the P3D as my EDC.

Sometimes, as Mies van der Rohe put it, less is more.
 

Confederate

Enlightened
Joined
Jun 22, 2006
Messages
360
This is all astounding to me. Not so much the lower low of the P3D (that's understandable in a situation where you want longer runtimes), but what floored me was what a good deal the Fenix Store was offering with its package deals. Old L2D or P3D, both with FREE E01s. Computing it on a calculator, it works out to be an astounding deal. Figure discount. Figure base prices. Do some basic addition and subtraction and it's a deal I couldn't pass up!

I recall seeing the Q5s blowing away some of my older "bright" lights, but in those cases, outdoors, I could easily see the difference and I was blown away! Lights I'd always thought were brilliant now took a huge back seat to the new technology. Anyway, I'm glad to have it figured out. I'm also glad I have a few lights in each version. They're just great.

Thanks for your inputs.
 

baterija

Flashlight Enthusiast
Joined
Feb 7, 2008
Messages
1,053
I recall seeing the Q5s blowing away some of my older "bright" lights, but in those cases, outdoors, I could easily see the difference and I was blown away!

One thing that stands out to me is that Cree's binning structure is laid out roughly linearly by output at 350ma (a little under 7 lumens difference in each bin looking at the charts). This means the percentage difference is diminishing with each bin increase. Throw in the fact that we perceive those smaller differences as being even smaller, and we're facing some strongly diminishing returns with each bin jump. The wow factor for a jump of a bin or 2 may well be behind us.
 

Gator762

Enlightened
Joined
Mar 14, 2007
Messages
307
One thing that stands out to me is that Cree's binning structure is laid out roughly linearly by output at 350ma (a little under 7 lumens difference in each bin looking at the charts). This means the percentage difference is diminishing with each bin increase. Throw in the fact that we perceive those smaller differences as being even smaller, and we're facing some strongly diminishing returns with each bin jump. The wow factor for a jump of a bin or 2 may well be behind us.

Could be that Confederate has a higher bin CE edition light. I upgraded my L1D/L2D CE to an R2 emitter. It isn't much different than the Premium Q5. In fact, very difficult to tell on max. On low it looks like a slight difference.

Thanks to DarkZero for my R2 emitter! :)
 
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