# Reasons to use Cree P4 or Reasons to use Cree Q5?



## Weylan (Jan 24, 2008)

So I am trying to decide on going Cree P4 or Cree Q5 and I am trying to decide on which way to go. I have heard that the Q5 is brighter, but other then price is/are there some other reasons to choose P4 Vs Q5?
Things like forward voltage? Things like heat tollerance? Cost? Color white?

I do like cool white rather then warm white. Even at low current color shifts?


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## SteveDavis (Jan 24, 2008)

There are two types of binning that Cree does: color coordinates and luminous flux. The Q5 and P4 bins are two luminous flux bins. The only thing indicated by the flux bin is the brightness. There is a wide range of color bins available to both (though the warmer bins may only be available in P4).


Some people have claimed that the higher flux bins have a higher Vf, but that does not in any way indicate that the LEDs you receive will have a higher Vf if they come from the Q5 bin. Both bins have the same datasheet and are spec'd to have the same range of values for everything other than brightness.


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## glockboy (Jan 26, 2008)

Go with Cree Q5 WC or WB.


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## LukeA (Jan 26, 2008)

glockboy said:


> Go with Cree Q5 WC or WB.



Even when the Q5 costs twice as much as the P4 for 25% more light?


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## znomit (Jan 26, 2008)

The cost difference is often minimal if you look at the entire package, your time, batteries, mounting etc. 
3Q5s = 4P4s.

I went with R2s :twothumbs


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## kongfuchicken (Jan 26, 2008)

For portable lighting, go with high bins.
For fixed lighting, go with cheaper numbers.
YMMV


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## CM (Jan 26, 2008)

You guys realize that a 25% increase is not easily discernible by your eyes? I think going from P4 to Q5 is worthwhile. However, those that are paying a premium for an R2 over a Q5 are deluding themselves. The difference is less than 10%, something your eyes can't see. An integrating sphere, yes, but your eyes, no way.


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## VidPro (Jan 26, 2008)

yup put post 5 and post 6 and 7 together and that is what i would say.
get the best darn bin and item from the most reliable source WHEN:
1) your time is worth more than the differance in price
2) its only a 1 shot deal, and when its done its done
3) you already paid $20+ for drivers and $50+ for battery tubes, and $30+ for mods
4) the item your putting it in cost some 200$ bucks to begin with.

and you get an ol cheaper cree, which works just fine WHEN:
1) you can remove the item anytime, to change for the next wizz bang stuff , or when the price drops
2) its just an area light, and your using 30+ of them anyways
3) or a cheap mod, you just made a 20$ light a 50$ one, who cares if it looks 10% brighter to your eyes on max
4) your replacing 5mm leds 

stuff like that. because they did not change the original gate type of the led, and drive CURRENT makes a big difference in led voltage, that really has not changed so much for YEARS now, with any of the stuff. from any of my testing , its how hard you run it, and how well it was heat removed, (which can include age) that did any major VF things that change HOW most of the driving items work. pluss the drivers themselves, and the battery voltage. 
So to me i havent seen any huge differential in the voltage of the "white" led gates , that makes that much differance, even in Luxes, it seemed to be more gate fault and precision of parts, than some magical junction that worked at totally different voltage AT the same current and heat.
the gate voltages will change , when the gate itself is made of different materials, other than when damaged, heated, or manufactured better or worse.


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## LowTEC (Jan 27, 2008)

i honestly cannot tell the difference between my P4 and Q5 P2D in terms of output, always pic the wrong one when I try to find out which one I just paid premium on for a brighter output, I'm not impressed


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## yellow (Jan 27, 2008)

I can see a difference between my "P4 in expensive Sandwich Shoppe 19 mm reflector"-mod and "cheaper reflector using higher binned Cree"-lights.

So if I would only have to use three emitters instead of four, meaning one of the expensive McR-XRs less, less current and less space needed --> I'll take the bit more cost of three R2s  (compared to three P4s) over getting *four* cheaper P4s + four McRs instead


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## precisionworks (Jan 30, 2008)

> The only thing indicated by the flux bin is the brightness.



Not quite.

According to Cree, _All XLamp LEDs are tested and sorted by color and brightness into a unique bin.

_Group Q5 (107 lumen) is available only in Cool White color temperature. Group P4 (80.6 lumen) is available in both Cool White and Neutral White color temps. Neither the Q5 or the P4 are available in Warm White.



> I do like cool white rather then warm white.


Most users would select the Q5, because of the high efficiency, plus it's the color temp you like.

http://www.cree.com/products/pdf/XLamp7090XR-E.pdf


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## TorchBoy (Feb 5, 2008)

precisionworks said:


> Most users would select the Q5, because of the high efficiency


[Yawn.] See post 4.


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## SteveDavis (Feb 5, 2008)

precisionworks said:


> Not quite.
> 
> According to Cree, _All XLamp LEDs are tested and sorted by color and brightness into a unique bin.
> 
> _Group Q5 (107 lumen) is available only in Cool White color temperature. Group P4 (80.6 lumen) is available in both Cool White and Neutral White color temps. Neither the Q5 or the P4 are available in Warm White.



That is true, but not forever. There are chromaticity bins, and there are flux bins. P4 and Q5 are flux bins. Some chomaticity bins may not be available for all flux bins, but that doesn't mean that the flux bins say anything about color. In the future, someone looking back at this thread would be confused by your comment, as the Q5 will be available in neutral and warm white chromaticity bins at some point.


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