tiny review: Led Lenser P7.2

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Fritz t. Cat
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The 4 x AAA configuration makes up somewhat for the lack of regulation, in addition to allowing more of the battery to be used. A smaller fraction of the maximum battery voltage is the minimum forward voltage of the LED, compared to 3 x AAA, so the current is more stable than it would be with the lower voltage and lower resistance to have the same peak current. For simple mod., it is a great advantage, at least with NiMH cells.
I just ordered one from Fasttech! Smile

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

snakebite
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big problem is you WILL reverse a nimh cell.vf of the led will allow it to run ok on 3 cells.
if your cells are very consistant this is not as much of a problem(eneloops).

Fritz t. Cat wrote:
The 4 x AAA configuration makes up somewhat for the lack of regulation, in addition to allowing more of the battery to be used. A smaller fraction of the maximum battery voltage is the minimum forward voltage of the LED, compared to 3 x AAA, so the current is more stable than it would be with the lower voltage and lower resistance to have the same peak current. For simple mod., it is a great advantage, at least with NiMH cells.
I just ordered one from Fasttech! Smile
M4D M4X
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can you please explain that reversing a bit more?

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Fritz t. Cat
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Since there is no electronic driver, there is no low voltage warning. So if the cells are not matched, it may run one of them down to zero voltage or below while still running on the voltage of the other three. That would ruin a NiMH cell or make an alkaline cell leak. It is similar to the problem when running an SK-68 on a lithium ion cell, though not that bad. One should use only matched cells and change or recharge them when it gets dim.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

M4D M4X
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thanks!

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Fritz t. Cat
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In fairness to LED Lenser and to all those other brands that I usually consider to be too expensive for a second look, there is a very long dramatic thread here about Zeusray’s quality control problems.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

M4D M4X
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I used the zeusray because it was very popular that days and a lot members bought one…

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Fritz t. Cat
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I usually don’t see any significant advantage to the more expensive lights, so I have remarked about the apparently well chosen optics of the LED Lenser and about the problems with the later Zeusrays. The Zeusray is a good comparison for performance, but maybe not for price.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

M4D M4X
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you are right!

i bought the P7.2 for about 5 times the price of the zeusray – but its is not 5 times better
(exept “build quality”)

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Fritz t. Cat
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I have a P7.2 from Fasttech now. Though the pictures show the side with the blank flat, it does say LED Lenser on it. It comes with a multiple language users manual that says it is from Zweibrüder Optoelectronics GmbH, and in a box with LED Lenser inside and outside the top. I see no indication that it isn’t genuine. It looks to me that it is the same thing, just aimed at a more price sensitive market. But I don’t have a high priced one, sold as genuine, to compare it to.
It throws like a pretty hot aspheric, even with all its resisters still in the circuit. The only other light I have that puts nearly such a large fraction of the LED’s output into the main beam has another type of Fresnel lens. The transition from spot to flood is better than that of the Coast HP1 but not as smooth as that of an aspheric. I like the passive mode control, but I also plan to short out the resistors in the head. The manual brags about the fact that unregulated alkalines die slowly.
I am not sure about the aesthetics yet. It is simple, but it has a hint of cheapness in the shape (!). At least it is much better than the Coast HP1, though much worse than the Yezl t9. It needs anti-roll flutes, knurling on the head and more complex curves. They should hire a potter to prototype shapes and the NC lathe programmer that did the SS-5039.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

marcl
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Fritz t. Cat wrote:
I have a P7.2 from Fasttech now. Though the pictures show the side with the blank flat, it does say LED Lenser on it. It comes with a multiple language users manual that says it is from Twei Bruders, and in a box with LED Lenser inside and outside the top. I see no indication that it isn’t genuine. It looks to me that it is the same thing, just aimed at a more price sensitive market. But I don’t have a high priced one, sold as genuine, to compare it to. It throws like a pretty hot aspheric, even with all its resisters still in the circuit. The only other light I have that puts nearly such a large fraction of the LED’s output into the main beam has another type of Fresnel lens. The transition from spot to flood is better than that of the Coast HP1 but not as smooth as that of an aspheric. I like the passive mode control, but I also plan to short out the resistors in the head. The manual brags about the fact that unregulated alkalines die slowly. I am not sure about the aesthetics yet. It is simple, but it has a hint of cheapness in the shape (!). At least it is much better than the Coast HP1, though much worse than the Yezl t9. It needs anti-roll flutes, knurling on the head and more complex curves. They should hire a potter to prototype shapes and the NC lathe programmer that did the SS-5039.

Does it say twei or zwei bruders?

Marc.

Eagles may soar, but weasels don't get sucked into jet engines!

Fritz t. Cat
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It says “Zweibrüder Optoelectronics GmbH”. Sorry, my German is rusty and I didn’t look back at it before I posted.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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I give it a one and a half, on a scale where the “number 3 AA zoomie” and the Coast HP1 get zero and SK-58 and CNQ zoomy host are around nine and the Yezl t9 is ten.
I like the matte finish and the lack of fins on a moderate power light. On the other hand, there is too much corner at the base of the sliding head. There is no knurling at all on the head where it is needed to work the zoom. The matte finish gives good grip, but it would be easier to zoom if the head had more shape. It would also be nicer to hold if the handle had some shape to it.
Maybe worst of all, it looks like it could have been made from thin aluminum pipe with a little spinning but only minimal machining.
The zoom does move nicely. Partly because the head slides on two separated o-rings.

Added: the Zeusray wins on feel and appearance, especially on visibly being well made. I give it a five.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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I shorted out the resistors in the head, as shown above, to increase current. In my example, the LED is now over-driven in turbo mode. With the button held down it starts bright then turns blueish, apparently from over heating the phosphor. I will check between the star and pill.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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Sure enough! No thermal compound under the star.

I dabbed some Arctic Silver on the front of the pill, and it works fine now. I don’t have a small enough star shaped screw driver, but a regular flat one did it. There was some white stuff sticking the star to the plastic cover, I don’t know what for. I wonder whether they are all without thermal compound or if Fasttech gets rejects.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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A useful position is with the head slightly pulled back from full forward. The TIR reflector spot gets smaller and the aspheric lens part forms a halo around it.

In turbo mode it ran the cells down in 10 minutes, so it is drawing 3 or 4 amps. This is good with an XP-G2 with a direct thermal star and a solid pill, but it wasn’t good with no thermal compound between the small star and the pill. It was designed to have that much engineering margin for reliability. The lack of thermal compound is clearly a defect. The question is whether I saved half the price by doing my own quality control, or whether the full price ones also have used up their engineering margin in poor quality control.

Comparative beam shots later.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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With fully charged white Eneloops and a fully charged Efest 2.5 Ah, 35 A purple IMR 18450.
The LED Lenser is on high (not turbo) with the resistors in the head shorted out and Arctic Silver added.

Lenser on the left and a TangsFire C8 on the right

Lenser on left and Zeusray on right.

On one hand the Lenser is more expensive and has a simple mod. and a defect fixed. On the other hand, it has an XP-G2 and NiMH cells versus XM-L2s and an IMR cell in the other two. The optics is just a piece of thermal plastic. It can’t be expensive to produce in large numbers.

This is an early ZeusRay that works well as far as I know. The TangsFire seems to be a good example of a C8. There is some of the TangsFire’s spill behind the Lenser, but this is not a large effect. The Lenser is substantially brighter in turbo mode, but that required the button to be held down.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

M4D M4X
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thanks for your updates!

looking on my pictures I would say that there was thermal paste under my MCPCB

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Fritz t. Cat
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M4D M4X wrote:
looking on my pictures I would say that there was thermal paste under my MCPCB

I suppose a drop of heat sink compound in the right place is worth $30 or so extra, when you need it. I was lucky not to lose the LED. It really turned a light blue and became no brighter than on high.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

M4D M4X
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the difference between “good work” and “bad work” is often hardly measurable, but it can decide between life and death of people or semiconductors

(i am medical engeneer ;))

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Fritz t. Cat
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I have two Lenser P5.2s, but haven’t opened either up yet. (They perform so well stock that I didn’t want to dig out potting compound until I had a spare.) The first, from Fasttech, has no flaws that I have seen yet. The second, from Ebay and mailed China Post, has the tail cap o-ring in the wrong groove. I tried moving it to the same groove as on the other one, but the light didn’t work. Apparently the slot is too shallow or too narrow or the ring is too fat. This seems to support the idea that they direct seconds to the more price sensitive Asian markets.
The Pop Lite, and the Coast I have, seem to be different products, though some parts may be interchangeable. The tail cap from the Coast HP1 fits the Lenser 5.2.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

M4D M4X
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there are a lot of faked ledlenser out there…

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Fritz t. Cat
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I don’t think any of mine are fake, but I am not sure of the next one. Where have you seen them?

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

M4D M4X
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i just read of them on a statement on ledlensers homepage…
they said if its cheap its a fake Big Smile

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Fritz t. Cat
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From what I have seen, I don’t believe them. I haven’t taken the LED off one to check that the star is direct, but they are copper. The box, the sheath and the manual look authentic. The fit and finish are excellent. The lanyards don’t break when you tug on them. It is likely they are factory seconds, but I don’t believe they are imitations.
It makes good business sense to produce lights for Asia and sell them at a reduced price. Once engineering, advertizing and tooling costs are paid for, producing more units is not that expensive. They can probably sell them at a profit for a lower hole sale price, and, maybe more important in the long term, they can establish market in the countries where the biggest profits will be made in the future.
Does anyone know whether Leatherman multi-tools also are available at reduced prices from Asia?

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Chicken Drumstick
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I don’t think they are fakes. I suspect they come from the same factory. But just aren’t “official” licenced ones or not from an authorised agent.

M4D M4X
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the LED of the P7.2 died long ago (gas-dedomed bondwires do not like to be smashed with a TIR)

 

so i used a XP-L V4 to give back live to the light...

numbers and pics will follow!

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blitzwing
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No regulation eh?

I thought these were trumpeted as a properly current regulated light?

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just some resistors in series with the cells…

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Fritz t. Cat
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Current is limited by resistors, as with cheap lights, but 4 x AAA has more constant output than 3 x AAA, because more of the voltage drop is in the resistors and relatively less in the LED’s forward voltage.
No active electronics but the LED its self. Just resistors and a three way switch. Very German, even though it is of course manufactured in China.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

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