# High CRI (Warm white) 4 Sevens Preon 2 + Neutral White Comparison Review



## UnknownVT (Nov 11, 2011)

By the courtesy of 4Sevens I have on loan the new High CRI (warm white) Preon 2- as well as the current limited run Neutral White to look at.

Size -





the 4Sevens Preon 2 has been around a while now the size and appearance do not vary - they all look like the long black one (marked as the 1st gen Warm White)
I specifically asked for a couple of different colored Preon 1 bodies to show that one can play "lego" with the Preons - to configure them as Preon 1's with clickies. Normal cool white Preons do come in different colors as well - as shown in the blue colored Cool white Preon 2 - but that has the standard supplied plain end cap for the Preon 1 - which makes the light a twisty........
So this shows the Preon is a very versatile system light.

How do the High CRI, the current Neutral White compare with the standard Cool White?

This may be the best way -
do a show & tell....





Although the heads are are mostly black 
there is a difference between the warm whites and the cool or neutral whites 
in the emitter/reflector:





Enough of the introduction -
rubber meeting road -

High CRI (Warm) Preon 2 vs Cool White (1st gen) Max, NiMH







The High CRI being a Warm White shows distinctly as yellow/orange in comparison to the Cool White.

High CRI (Warm) Vs 1st Gen Warm White Max, NiMH







doesn't show so well in photos - but the High CRI seems to show paler yellow going toward pale green - the 1st gen Warm White seems pink/browner to my eyes

High CRI (Warm) vs. current gen Neutral White - Max, NiMH







what surprised me was how *UN*yellow the Neutral white was - in fact when I first got the Neutral white I thought 4Sevens had mistakenly sent me Cool White!!

This probably means that 4Sevens got a higher color temp bin of Neutral White - perhaps not the fabled 3A (I wish) - but it seems closer to the 4 bin rather than the previous 5A3 or 5B3s.......

Neutral White vs. 1st gen Cool White, Max, NiMH







this comparison illustrates how cool these current Neutral Whites are, if I were guessing - they are possibly 4A or B's? 
I am really liking these as they do almost give a "neutral" color at night when yellow tungsten (2700deg K) is prevalent.


So how does the High CRI work out?
To be very honest I found it very, very difficult to tell - 
especially when I compare the new High CRI and the 1st gen Warm White.

Probably the best way is to just present the photos I took of homemade Macbeth color chart -
and place them next to each other 
(I think CPF is arranged in such a way that I can no longer see my beamshots laid out next to each other horizonatlly - at least on my monitor - hopefully some with higher resolution and/or wider monitors can see that the comparison beamshots are laid out in pairs?)

















I can see the desirability of having High CRI 
(I believe that is one of the reasons for the slower acceptance of LEDs in general lighting - cost being the overriding one for now)

However on this look-see - subjectively I was very pleasantly surprised by this variant of the Neutral White - which looks a lot cooler/whiter than the two previous limited runs of 4Sevens Neutral Whites - I managed to mislaid my Preon Neutral white - 
but I do have both limited runs of the Quark AA variants that I can do comparison beamshots to the current Neutral White - if there is any interest.


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## mvyrmnd (Nov 11, 2011)

> doesn't show so well in photos - but the High CRI seems to show paler yellow going toward pale green - the 1st gen Warm White seems pink/browner to my eyes



That's been my observation as well. The CRI is higher because of the boost in Cyan output. The standard warm emitter always looked very pink because of it's high Red output. The higher Cyan in the HCRI counteracts this and the colour is much more balanced, in my eyes at least.


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## UnknownVT (Nov 11, 2011)

mvyrmnd said:


> That's been my observation as well. The CRI is higher because of the boost in Cyan output. The standard warm emitter always looked very pink because of it's high Red output. The higher Cyan in the HCRI counteracts this and the colour is much more balanced, in my eyes at least.


Thanks for the corroboration.

That sounds very logical.

However another possibility is the actual binning -
and if we followed your logic about the difference in appearance - then choosing a bin that tends more toward green and blue (ie: cyan) would then result in higher CRI - this unfortunately is not the case.

I also think this way, and have coveted the bin 3A which is about 5000+deg K - but I have been told this bin although in Cree's books as Cool, Outdoor and Neutral whites - 3As do not seem available - 

As a bin that is cooler than warm or neutral should have more blue 
and being warmer than cool white ought to have more reds/yellows - 
giving a very good compromise - thus possibly higher CRI - but this just not so - 
most LEDs on the Planckian Locus have good approximation to the same color temperature lights - 
but they have poorer CRI due to PEAKs in their spectrum - 
so much so that there were proposals to measure the CRI for LEDs differently(!) 
- the purported support for doing this is because LEDs seem to render colors better than their pure CRI would indicate.

Just to show the practical worth of CRI 
and how it could be misunderstood and 
placing too much importance upon -

Everyone knows how difficult to it is to read yellow print on white 
and distinguishing navy from black 
under tungsten light -

Yet the standard commonplace tungsten light bulb has a CRI =100 ie: _PERFECT_!


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## Harry999 (Nov 12, 2011)

Thank you for the review. I definitely feel some comfort with the two Preon 2 High CRI models I have ordered. The chart showed richer colours under High CRI to my eye. Looking forward to using them.


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## abras (Nov 12, 2011)

What's the difference in output between WW 1st gen. and new Hi CRI ?
WW 1st gen. was too dim and yellowish for me compared to CW.
In Mini CR2 on Max. it was closer to Mid on CW.
So is there any OTF lumens improvement in Hi CRI ?


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## Houdiny (Nov 12, 2011)

ITPython said:


> Great review. You wouldn't happen to have any incandescents lying around to do a side-by-side with the HCRI would you? (just for tint comparison purposes)
> 
> Also when you mention the HCRI leans towards a pale green, how green is it?



Here are some pictures I took for cct/tint/color rendering comparison purposes. One of my contestants is my incan Surefire M3 with HO bulb, one of the others is my Ti Quark, modded with a HCRI (90+) XP-G.
http://www.candlepowerforums.com/vb/showthread.php?321243-CRI-tint&p=3736435&viewfull=1#post3736435


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## mvyrmnd (Nov 12, 2011)

And here's a 7 light CCT/CRI comparison that I did a while ago that includes an incan and a 1A,5A and 7A bin Cree, 7A3 HCRI Cree and a 5700K SST-50

And yes, LED's have a very "peaky" output. High CRI emitters tend to have a flatter output, hence a wider spectral output, hence Higher CRI. CRI is not, however, directly related to CCT, which explains:



> As a bin that is cooler than warm or neutral should have more blue
> and being warmer than cool white ought to have more reds/yellows -
> giving a very good compromise - thus possibly higher CRI - but this just not so -



So the warm emitter puts out a lot more red than a cool white emitter cchanging the CCT (but not necessarily the CRI) but there's a big trough in the output at the cyan wavelength, pushing the colour balance towards brown/pink. The flatter output of the HCRI emitter fills in the trough at that wavelength, pushing the colour balance back to a more neutral place (but that would look green if your eyes were used to the output of the standard WW emitter). This does not affect CCT (believe me when I say I don't understand why, but I know that it is true, after reading posts of much much smarter members here)


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## js82 (Nov 12, 2011)

UnknownVT said:


>



Nice comparison picture there with the color palettes. Would you mind doing it with midday sunlight?


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## ma_sha1 (Nov 12, 2011)

I can't tell the High CRI apart from the regular warm white


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## tbenedict (Nov 12, 2011)

I'm struggling to see the CRI difference myself. It might just be how my laptops display represents the color and it will be more obvious when I have one in hand.

The prior warm run had two tints, one was more rosy than the other.


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## burntoshine (Nov 12, 2011)

i would love to see the color chart with sunlight AND with the 2nd run XPG (not the most recent NW run) of quark neutrals. the most recent NW run was an ugly green cool white; it was not neutral at all in my opinion.

i was considering getting a high cri quark, but i'm really hesitant at the moment.

thanks for the review!!


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## lateralus180 (Nov 12, 2011)

burntoshine said:


> i would love to see the color chart with sunlight AND with the 2nd run XPG (not the most recent NW run) of quark neutrals. the most recent NW run was an ugly green cool white; it was not neutral at all in my opinion.
> 
> i was considering getting a high cri quark, but i'm really hesitant at the moment.
> 
> thanks for the review!!



I have three High CRI lights in the mail that should arrive today. Quark 123, Mini AA, and Preon 2. I also have on hand a Mini AA and Mini 123 with the XP-E Q3 5A or 5A3 tints. I will see if I can take accurate beamshots tonight, but I don't know if my iPhone 4 will accurately represent. I have the most recent run of 4S neutrals as well. I'll see if I can add a comparison with the HCRI and my 3D Maglite.


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## CarpentryHero (Nov 12, 2011)

Thanks for the review, looking at the pic. I only notice a difference in the white border of the two. I traded my old warm white quark for a nuetral XML head, then bought a hi cri 123. This way I don't have such an overlap.
How thick is the preon two though, decent pen light replacement? 

I read some where in the led forum that the old warm white are around 80 cri. And that the new hi cri quarks have three bins they use so you may end up with better than 85 cri.


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## UnknownVT (Nov 12, 2011)

js82 said:


> Nice comparison picture there with the color palettes. Would you mind doing it with midday sunlight?


Not at all...
in fact I meant to post this - but there was just too much hurry on my part - thanks for prompting me, and I'll edit to add this in the opening post:





While I'm at it - a real GE "soft white" 60watt incandescent bulb:







ITPython said:


> Great review. You wouldn't happen to have any incandescents lying around to do a side-by-side with the HCRI would you? (just for tint comparison purposes)



Streamlight Scorpion incandescent


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## ryguy24000 (Nov 12, 2011)

Very interesting. Thanks for the review.


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## mvyrmnd (Nov 12, 2011)

tbenedict said:


> I'm struggling to see the CRI difference myself. It might just be how my laptops display represents the color and it will be more obvious when I have one in hand.
> 
> The prior warm run had two tints, one was more rosy than the other.



That's another good point I forgot. The gamut that your computer screen is capable of displaying is quite small, and unless you've had it properly calibrated, you can't trust its output. The ONLY way to get a proper comparison is to see it in person.


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## HIDblue (Nov 12, 2011)

Nice review and great photos! I don't know...call me silly, but I still prefer the Neutral over the Warm or High CRI...


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## Harry999 (Nov 12, 2011)

HIDblue said:


> Nice review and great photos! I don't know...call me silly, but I still prefer the Neutral over the Warm or High CRI...



Not at all. We buy the lights and use those that meet our personal preferences.


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## js82 (Nov 13, 2011)

UnknownVT said:


> Not at all...in fact I meant to post this - but there was just too much hurry on my part - thanks for prompting me, and I'll edit to add this in the opening post:


Thanks!

I see some differences in colors but I don't know if it's cuz of my screen. Which one do you think looks closest to sunlight?


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## UnknownVT (Nov 13, 2011)

js82 said:


> I see some differences in colors but I don't know if it's cuz of my screen. Which one do you think looks closest to sunlight?



This is pretty subjective -
the cool white ought to be closest to daylight D65 - which is color temperature of 6500K - that is supposed to be noon daylight with clear blue skies - but I find it slightly blueish

Sunlight is supposed to be 5500K ("D55" if it exists - the closest standard is D50 @ 5000K)
the current batch of Neutral Whites seem warmer than D50 (I have CRI90 D50 fluorescent "Sunlight" tube to compare) - but the current Neutrals seem close enough that I actually on first sighting thought 4Sevens had sent me Cool White instead -
so in this batch (and I freely admit my bias) the current Neutral White seems closest to D50.
the Cool white definitely shows as too blue and the High CRI (warm) is definitely too amber/yellow.

If I have some time I'll take photos of these lights on white paper that's illuminated with D50 lighting.

In the meantime read these - please -

Most of us "see" common tungsten lighting as "white" 
(even though a lot do know it is very yellow/amber when compared to sunlight/daylight). 

There is a very good reason for this, 
as our eyes/brain adjusts for what we perceive as "white" for different light levels, 
please see:
_
Kruithof curve_ - Wikipedia, the free encyclopedia

The _Color of White_


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## UnknownVT (Nov 13, 2011)

UnknownVT said:


> This is pretty subjective -
> the cool white ought to be closest to daylight D65 - which is color temperature of 6500K - that is supposed to be noon daylight with clear blue skies - but I find it slightly blueish
> 
> Sunlight is supposed to be 5500K ("D55" if it exists - the closest standard is D50 @ 5000K)
> ...



I did both GE 5000K "Sunlight" CFL (Compact Fluorescent Light) 
and GE 6500K "Daylight" CFL - 

these bulbs may not have color temperatures accuracy to the least significant digit 
- but are probably "good enough" for our comparison purposes - 

Another note, if it means anything - both the CFL's have CRI=82 
(but more than likely very different deviations from "perfect" to any of the LEDs)

Flashlights on paper illuminated with -
GE 5000K "Sunlight" CFL

















GE 6500K "Daylight" CFL
















These are good for seeing how the lights differ from reasonably well known standard color temperatures of 5000K (D50 - tiny bit warmer than "sunlight") and 6500K (D65 - "Daylight")
The exposures were auto as-is with Fixed Daylight White balance -
_*NO*_ post processing adjustments for tint or color.

I then did some post processing to try to get the pictures to look like I saw them - the main problem was in balancing the flashlight hotspot (which was much brighter) to the surrounding areas illuminated by the CFLs.

Details I selected a grey point (should be neutral grey) near the lower left corner - the furthest point from the flashlight beam - so ought to be the CFL light only - then did minor adjustment to the brightness so they'd all look similar in brightness. Therefore there is some color/tint adjustment (but it is everything in the whole picture) due to the grey point selection - I was hoping that this would be an "idealized" way to see the pics, as the "white" paper is supposed to be tint/color free - as it was, I don't think I was that successful - but I present these without any further excuses -


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## js82 (Nov 13, 2011)

UnknownVT said:


> This is pretty subjective -
> the cool white ought to be closest to daylight D65 - which is color temperature of 6500K - that is supposed to be noon daylight with clear blue skies - but I find it slightly blueish
> 
> Sunlight is supposed to be 5500K ("D55" if it exists - the closest standard is D50 @ 5000K)
> ...



Those are very interesting articles. No wonder somebody on this forum said that their vision adjusts to the color temperature. So in fact it adjusts because of the total brightness level rather than just due to the overall color temperature.


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## bodhran (Nov 13, 2011)

How true a color the camera shows I don't know, but to my eyes the HCRI and WW beam shots look identical. This isn't a complaint because I ordered a Mini CR123 for the tint as much as the CRI. I'm never without my warm CR2 and I think it does very well rendering colors, though doesn't compare to my HDS HCRI.


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## UnknownVT (Nov 19, 2011)

I posted the below in another thread - but thought it may be appropriate to post it here:

CRI is not that simple to understand - and I claim no expertise in it - 
However CRI is always in reference to a "black body" radiator of the same color temperature - so for a cool white or a white that approximates to sunlight - those would be compared to the "black body" of actual "Daylight" or "Sunlight" - this is not as easy as it sounds since those are nature and can easily vary from day to day and season to season - so the CIE has developed standard ("white") illuminant of D65 (normally called daylight at 6500K) and D50 (@ 5000K which is actually a shade warmer than noonday sun only (no sky) which is normally regarded as 5500K = D55 (actually also a CIE standard illuminant).

Artificial light - at one time the most prevalent household lighting was/is tungsten light - about 2700K - just from this color temperature alone one knows this has to be significantly warmer tint/color than daylight or sunlight.

However the BIG trick for CRI for artificial light - is the approx black body for tungsten lighting is actually the tungsten light itself - so by definition a tungsten light bulb has CRI=100.

Yet just about everybody knows that it is very hard if not impossible to read certain shades of yellow printing on white and really difficult to distinguish navy from black (try picking these socks in household lighting).

So what's the value/worth of CRI in this instance -
well we can say if a light renders color the same way or how much it deviates from a tungsten bulb....

OK....
is that worth anything?

In the case for medical type application - perhaps because traditional inspection lights have just about all been tungsten based - so a light that approximates to tungsten is "good" -

BUT think on this what if a light emphasized certain color like reds and orange - so that certain anomalies get highlighted/emphasized by the light may be better for that type of inspection - but since that would deviate from a tungsten light, the CRI by definition would be lower, and could actually be abysmal - yet I would think it may actually be more useful than a High CRI warm white that approximates to tungsten (to get the High CRI).

Take another rather silly example just to illustrate my point - - UV dye detection - we will not see these under and normal light even with high CRI - yet using UV rich light - like some blue LEDs will make these visible - so which light do we actually see the UV dyes better with - obviously the UV rich light - but these will have CRI probably in the single digits - ie: pretty awful CRI......

Ah! I hear you all argue this is a silly example and taking a specialized case -
As far as I know medical practice is specialized, being able to see skin/flesh anomalies is a specialized study - most of us lay-people do not go round looking for those, with or without flashlights - so if a flashlight was designed and wavelengths tuned to highlight or emphasize those anomalies - I would bet their CRI would not be that good....... 
so much for High CRI -


So as far I am concerned CRI is just not too well understood -
we are also too enamored with numbers - a CRI=100 may not always be "perfect" -
if it were why can't we see yellow print on white 
or pick navy from black under a light that is rated CRI=100?


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