P1D CE vs U2

Wiz · Dec 28, 2006

The spec of the P1 Cree is very impressive, 135 lumens for an hour from 1 CR123 when the U2 only manages 80-100 on 2 of them, for the same length of time. I couldn't wait to try them side by side. To see the tiny P1 Cree blow the relatively huge U2 away would be quite something....

...errr no. On a white wall they look almost similar, but out in field at the back of my home, in the winter blackness looking along the hedgerows, the U2 throws out substantially more light. Don't get me wrong, the Cree is impressive for its size and the meters do seem to show it as being the brightest, but out in the field, there is no doubt whatsoever that the U2 is putting out more light. It lights a much bigger area and makes picking out detail much easier.

On the excellent flashlight reviews site, they do a pretty good measurement of total light output (see here ). The P1 Cree measures 7850 for total output on it's brightest setting, whereas the U2 only manages 5500. Given the manufacturer's quoted outputs, that seems about right, so can anyone tell me why the U2 actually seems so much brighter in the real world? They were both running brand new batteries of the same make.

greenLED · Dec 28, 2006

Wiz said:
The spec of the P1 Cree is very impressive, 135 lumens for an hour from 1 CR123 when the U2 only manages 80-100 on 2 of them, for the same length of time.

It's surprising how much light the XR-E gives out, especially when you consider how differently these 2 different LED's are run.

Wiz said:
On a white wall they look almost similar, but out in field at the back of my home, in the winter blackness looking along the hedgerows, the U2 throws out substantially more light. Don't get me wrong, the Cree is impressive for its size and the meters do seem to show it as being the brightest, but out in the field, there is no doubt whatsoever that the U2 is putting out more light. It lights a much bigger area and makes picking out detail much easier.

Could you be confusing throw with total output?

My new U2 is noticeably brighter than an XR27-C I just had the chance to play with, and that's not only when looking at the beam, but also doing a ceiling bounce test. (but see my first comment)

Hellbore · Dec 28, 2006

Pics or shens!!!

EngrPaul · Dec 28, 2006

The Huntlight FT-01 Cree has more lighting levels and runs off 2 CR-123's or 2 RCR-123's. It also has a tail clicky.

Wouldn't that be a fight more fair against the U2?

greenLED · Dec 28, 2006

Hellbore said:
Pics or shens!!!

Here you go.

Wiz · Dec 28, 2006

greenLED said:
Could you be confusing throw with total output?

I understand the difference, and I know that I'm not measuring either scientifically, but there is a very substantial difference between the two when out in the field. The U2 penetrates the night better, lights the target brighter and lights a bigger target. Not by loads, but by a noticeable amount. I've been wondering if the Cree flashes brighter, but has a slower cycle than the Luxeon or something like that. Certainly that might explain some of its efficiency.

chevrofreak · Dec 28, 2006

Per my own measurements of 1 P1D CE and 2 Surefire U2's

Fenix P1D CE - high - Energizer E2 CR123a: 1556 - (estimated 111.14 lumens)

Dizzy's Surefire U2 - Level 6 - Rayovac RL123a: 1572 (estimated 112.29 lumens)

4sevens Surefire U2 - Level 6 - Surefire SF123: 1261 (estimated 90.07 lumens)

Those numbers are from my home made integrating sphere.

cdosrun · Dec 28, 2006

Wiz said:
I've been wondering if the Cree flashes brighter, but has a slower cycle than the Luxeon or something like that. Certainly that might explain some of its efficiency.

There shouldn't be any 'flashing' with the P1D-CE, it is current regulated so the LED is running continuously and, as far as I know, a U2 is the same.

I think (without owning a U2 personally) that the likely difference is in the distribution of power throughout the beam. Newbie posted a nice diagram representing the large increase in lumens required to make the spill beam noticeable brighter, and the P1D-CE is. Mine only arrived this morning and whilst bright, there is a lot of light in the spill rather, leaving less in the spot.

I don't have any LuxV lights, so I am only rambling, but I would imagine the light distribution would be quite different with such a large die.

A

p.s. - ignore everything I said, Chevrofreak has the answer!

greenLED · Dec 28, 2006

cdosrun said:
I think (without owning a U2 personally) that the likely difference is in the distribution of power throughout the beam. Newbie posted a nice diagram representing the large increase in lumens required to make the spill beam noticeable brighter, and the P1D-CE is. Mine only arrived this morning and whilst bright, there is a lot of light in the spill rather, leaving less in the spot.

Exactly my thoughts.

Looking at chev's numbers, it also may be dependent on the individual emitters being compared.

dizzy · Dec 28, 2006

chevrofreak said:
Per my own measurements of 1 P1D CE and 2 Surefire U2's

Fenix P1D CE - high - Energizer E2 CR123a: 1556 - (estimated 111.14 lumens)

Dizzy's Surefire U2 - Level 6 - Rayovac RL123a: 1572 (estimated 112.29 lumens)

4sevens Surefire U2 - Level 6 - Surefire SF123: 1261 (estimated 90.07 lumens)

Those numbers are from my home made integrating sphere.

What did I win for having the most lumens? :lolsign:

THE_dAY · Dec 28, 2006

does your u2 have a warmer tint compared to the p1d-ce.

warmer tints will do much better out in the field.

Tremendo · Dec 28, 2006

I directly compared my U2 with my P1D-CE via personal use, and here is what I found:

1) Overall light - about the same.
2) Throw - about the same, as well as the spill.
3) Beam color - U2 looks yellowish, P1D-CE looks blue/white. Both are very useful.
4) Feel - U2 is more solid and has tactical switch, better feel. P1D-CE is much smaller.
5) Batteries - 1 CR123 vs 2 CR123.
6) Levels - U2 - easy to change levels, P1D-CE adds strobe, but tougher to get to, semi-ok turning.
7) Price - $70 for P1D-CE, $215+ for U2.

I love my U2, but I bought another P1D-CE as a present already.

Somy Nex · Dec 28, 2006

cdosrun said:
There shouldn't be any 'flashing' with the P1D-CE, it is current regulated so the LED is running continuously and, as far as I know, a U2 is the same.

I think (without owning a U2 personally) that the likely difference is in the distribution of power throughout the beam. Newbie posted a nice diagram representing the large increase in lumens required to make the spill beam noticeable brighter, and the P1D-CE is. Mine only arrived this morning and whilst bright, there is a lot of light in the spill rather, leaving less in the spot.

I don't have any LuxV lights, so I am only rambling, but I would imagine the light distribution would be quite different with such a large die.

A

p.s. - ignore everything I said, Chevrofreak has the answer!

owning the U2 & P1D CE i think you've hit the nail on the head. the U2's beam is described as a "ram of light" and is sort of poised between throw and flood. it's beam angle isn't the widest, but it does focus most of the light within that angle.

the P1D CE on the other hand, has a smaller spot, but a wider angle/area of spill. indoors, such as in the beamshots in my sigline, it's easy to see this, as the light is being reflected back at you. outdoors, this may or may not have an advantage, depending on what you're trying to illuminate. brighter spill could either provide better context & field of vision through a wider area of illumination, or could just go off into wide open space.

SF U2 Lvl1/max, 1x18650:

P1D CE max/high, 1xCR123:

KDOG3 · Dec 28, 2006

You guys are going to force me to break down and get one of these P1D CEs' aren't you?

greenLED · Dec 28, 2006

Somy - love your beamshot pics!

Somy Nex · Dec 29, 2006

i tried to reload this page to see what i posted, but it took me half a day to do that =P i guess they're still repairing the cables from the quake damage in Taiwan

daveman · Dec 29, 2006

Wiz said:
I understand the difference, and I know that I'm not measuring either scientifically, but there is a very substantial difference between the two when out in the field. The U2 penetrates the night better, lights the target brighter and lights a bigger target. Not by loads, but by a noticeable amount. I've been wondering if the Cree flashes brighter, but has a slower cycle than the Luxeon or something like that. Certainly that might explain some of its efficiency.

I venture to guess it's the warmer tint of that Lux V in the U2 that's making you "see" better out in the fields. According to flashlightreviews.com (RIP), the P1D CE does better in BOTH throw and overall output than the SF U2.

goldenlight · Dec 29, 2006

Hmm. Unless I missed it, nobody has brought out something that seams obvious to me: the US has a HUGE reflector, compared to the tiny Fenix P1D CE.

Wouldn't this make a big difference in the overall performance of the max output level of the U2?

When you compare reflectors, it isn't the diameter that's the improtant in comparing them: it's the AREA of the reflector, which enables it to gather and throw a lesser amount of light more efficiently than the brighter Fenix, with it's tiny reflector.

I don't have the diameters of both of them (and I'm too lazy to look them up) but if you calculate the area of the U2 (pi x radius squared) you'd see the huge adavantage the U2 has over the tiny area of the Fenix's reflector.

Put that Cree in a U2 reflector and you'd see it would blow the stock U2 out of the water.

Wiz · Dec 29, 2006

THE_dAY said:
does your u2 have a warmer tint compared to the p1d-ce.

warmer tints will do much better out in the field.

Yes it does, so that might well explain it. I've just compared the two with various light meter tests and the P1 on high won them all. I actually have 2 P1 Crees, one has a slightly warmer tint but shows as (very) slightly less bright on the meter. I'll try the warmer one against the U2 tonight.

Wiz · Dec 29, 2006

goldenlight said:
Put that Cree in a U2 reflector and you'd see it would blow the stock U2 out of the water.

So the next question is, f course, is are there any modders out there who'd mod my U2 to a U2 Cree, for a fee of course :naughty: :grin2:

P1D CE vs U2

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