Friday, November 30, 2012

In Defense of Tint Snobbery

You want a Hi CRI light.  You might not know it yet, but trust me, you do.  Let me persuade you:



If you watch the forums closely, especially CPF, you'll find a vocal and passionate minority of people that will accept nothing other than Hi CRI emitters.  These are the folks that held their Surefire Incans tight to their chests well after the rest of us had moved on the the icy illumination of LEDs.  They are to lights what fountain pen people are to regular pen addicts.  After having a wide range of lights to review and sample, including a few neutral and Hi CRI options, I can safely say that I like more revealing LEDs.  I am not a tint snob, I don't require a Hi CRI emitter, but if given a choice I'd happily sacrifice a few lumens for a Hi CRI emitter.

What is Hi CRI?

I am by no means an expert on colorimetry or an engineer, so this is going to be a rough and dirty guide.  Here is the wikipedia article on colorimetry.  Here is the wikipedia on color rendering.  Here is a great thread from CPF by the guru of illumination himself, McGizmo.  Here is some more information on CRI with some really good examples and photos. 

Hi CRI is generally an LED that has a color rendering index of 85 or higher.  That definition simply leads to another question--what is the color rendering index?  The color rendering index is a measurement of properties of light.  Specifically, it is a measurement of how accurate a light source is at illuminating colors.  That is, how good of a job does a given light source do at making reds look red and greens look green?  Note that color rendering and color temperature are two different things, but they are somewhat related.  We are all more familiar with color temperature from our experiences buying light bulbs at big box stores.  Color temperature is measured in Kelvin or K.  It analyzes where on the spectrum of colors a given light source is, with warm tones like red and yellow on one end (2,000-3,000K) and cool tones like blue and green (7,000K) on the other.  Here is the wikipedia article on that.  Think of it this way--color rendering measures what the light does and color temperature measures what the light is.  I know that is not exactly right, but it is close enough to make the difference intelligible. A light with a warm or neutral LED has a better CRI than a cool one, but being a warm or neutral LED is not the same thing as being a Hi CRI LED. 

The color rendering scale is pretty simple compared to the color temperature scale.  A light source that renders colors perfectly receives a score of 100.  The sun, on a sunny day, is the standard for perfect color rendering; it gets a score of 100.  After some extensive searching, the very highest score I can find for a manmade source is a CRI of 98.  The Solux halogen bulb has a CRI of 98.  It is used in art galleries and movie studios to bring out the finest colors possible and, in film, to make scenes shot inside to appear as though they were shot outside.  The LED in the Sundrop from McGizmo, a Nichia emitter, has a CRI of 93.  The traditional "cool" LEDs have a CRI around 70 (this comes from CREE itself, the makers of the XPG emitters).  Their cool emitters hit 70 while the neutral ones hit around 75.

All of this is nice, but why does color rendering matter?  Well, simply put, better color rendering makes lights more useful.  Part of the reason why sunlight is so amazing is because it allows the eye to pick up VERY subtle differences in color and these differences in color mean things.  For example, last Friday I was grilling pizza, which I really like to do, but as winter approaches the amount of light at dinner time, especially on the East Coast, is very small.  So I was grilling in the dark.  That day I happened to be carrying my Eagletac D25a flashlight, which I bought in warm.  The difference between the images of the pizza with a regular cool LED and the warm LED were tremendous.  I was able to tell when the cheese had achieved that golden brown color indicating that the pizza was done.  With the cool LED this is very difficult to do.  And this was just the difference between a cool and warm LED.  A Hi CRI light would have been even more revealing.  It is a difference you can't appreciate until you see it in person.  Here is a quick video demonstrating the beauty and power of a Hi CRI light:

        

If that video does not convince you to at least consider a Hi CRI light I don't know what will. 

How does it work?

Traditionally, incan lights were the only way to get good color rendering.  This was the reason why a lot of people still sought out these lights despite the waves of LEDs coming to market.  But LED makers have heard the shrill cry of those that hate cold light and have worked to improve their LEDs color rendering.

There are two ways to make an LED render colors more accurately.  Here is some more information on these two methods.  First you can have a light with multiple colors, all of which turn on at the same time.  Usually, these lights use a red, green, and blue emitters on a single chip.  This method is both complex and expensive.

There is a second method that is less expensive and less complex.  It is also more widely used and that is the introduction of "phosphors" into the LED.  Think of these phosphors as tinting the light.  The light goes out from the LED, interacts with the phosphors, and then comes out the light in a warmer and sometimes higher CRI than it was at the source.  This method has one major drawback--it cuts down on lumens.  Anything--a hand, a less transparent lens, or even phosphors that is between the light source and your eye makes the light appear less bright.  You need to know going in that a Hi CRI light based on the second method, will appear less bright.  There are less lumens coming out.  So it is a trade off--better color rendering or brighter light.  Generally Hi CRI lights and lights made warm by adding phosphors are 80-85% as bright as their cool LED brethren.

There is a third method, developed by an LED maker OSRAM, that combines the two methods reducing the complexity of the RGB LEDs and boosting the efficiency of the phosphor LEDs all in the same light.  They are not generally used in the flashlight world, but in lights for art galleries and surgical suites, places where color rendering REALLY matters, they are popular.   It would be nice to see this trickle down into lights and I really loved the OSRAM Golden Dragon emitter on my Nitecore EX10 back in the day.     

Hi CRI Lights 

Manufacturers and custom makers have taken notice of the desire for better color rendering.  There are now quite a few lights that come in warmer color temps.  But for the very best color rendering, aim for a true Hi CRI light.  Warmer LEDs will get you part way there, but true Hi CRI should be the goal.

Here is a thread of Hi CRI and Neutral lights drop ins from CPF.  A lot of these lights, like the 47s and the Sunwayman, are limited runs and may not be available outside the secondary market.  And now for the big list, drawn from the CPF thread, with updates and additions:

47s
*High CRI Preon 1
*High CRI Preon 2
*High CRI Quark 123
*High CRI Quark 123 2
*High CRI Quark Mini 123
*High CRI Quark Mini CR2

Armytek
Predator

Cabela's
*N Series light (technically not a Hi CRI light as it has a CRI of 80, not 85)

Cool Fall
Tri-V and Tri-V v.2

HDS Systems
EDC-E1S-Hcri
EDC Rotary

Mac's Customs
Tri EDC (limited availability)

McGizmo
Haiku
Mule
Sundrop

Peak
Eiger
El Capitan
First Responder
Logan
Night Patrol 300
Search and Rescue 450
Volcan

Prometheus Flashlights
XP18-B

Steve Ku
40DD

Sunwayman
Sunwayman V11R Hi CRI

Terralux
 (NOTE: Terralux does not publish its CRI numbers)

Lightstar 80 
Lightstar TruColor

TorchLAB
(NOTE: the specs list the Nichia 219 LED, which can be Hi CRI, contact Oveready for CRI numbers)
Moddoolar
Triple Copper E2E (full size and cut down)

Zebralight
SC51c
SC80c (also takes CR123a batteries)
H31c

H51c
H51Fc
H502c
H502d 

Bold: takes AA
Italicized: takes AAA
*: out of production

Lights with RGB output (the other way of getting more accurate color rendering, though neither light is Hi CRI):

47s
*Quark RGB

Surefire
Kroma

This list is probably not 100% accurate and comprehensive, but it is better than the next best list I could find, which is the CPF thread linked above.

Recommendations

If I were looking for my first Hi CRI light, I would almost certainly start with the TerraLux Lightstar 80 as it has the lowest barrier to entry.  It is a competitor to the Streamlight Stylus light, a well regarded light it its own right.  It is cheap and runs on common batteries.  If you later decide you don't like the light you can simply trade it or stash it.  It won't kill your wallet and you get to see whether or not you like the Hi CRI emitter (trust me, you will).

If you know you like or want Hi CRI and are looking for a good EDC light, I would probably go with one of the Zebralight options, probably either the SC80c or the SC51c.  I have not seen either in person, but I have handled some Zebralight stuff before and it is really high quality and Zebralight is a USA company.  The ability to make it a headlamp and the preattached clip are also huge pluses in addition to the golden light it produces.

If you want punch with your color rendering either the Prometheus or the Oveready will provide you with lots of sunlight-like lumens.  Both lights are beasts and both require special batteries, but if you want to turn on the Bat signal AND have good color rendering, these are your only options.  I have reviewed both (as evidenced by the links) and both are superb lights.  

Finally, if you want the King Daddy of all Hi CRI lights the McGizmo Sundrop is pretty much unrivaled in its color rendering in the flashlight world.  Its pretty much unrivaled in any illumination format.  It produces light that is as good or better at color rendering than the lighting in all but the highest end art galleries and surgical suites around the world.  It comes in the Ti-licious McGizmo clicky pack body meaning you can swap heads between the Sundrop and the Haiku, depending on your needs that day.

Another note, lots of folks on CPF mod lights to include Hi CRI emitters so if you have a favorite light body but hate the emitter, stop over at CPF and see if anyone can help you out.  MilkySpit has a excellent reputation as a modder, but he is really in demand.

Hopefully now you will be a tint snob too.   Also, I just checked, the Haiku is still available in Hi CRI, so that is an option if you win the Haiku Giveaway.   

9 comments:

  1. Hey Tony, quick question. In your opinion, where does the Aeon lie when it comes to this tint subject? Would you be able to likewise tell if the cheese on a pizza is golden brown?

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  2. The tint on the original Aeon is a bit green, so no probably wouldn't pass the golden cheese test. The new Aeon will be sporting a much better LED. We'll have to wait to see if it passes the test.

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    1. In fact here is a quote from Enrique:

      The 4500K 92 CRI Nichia 219 LEDs should be here in the next couple of days as well...

      One point less than the Sundrop which hits 93 CRI.

      Oh geez....

      Delete
  3. From the forums, I understand that the Aeon used to (out of production now) come in a neutral and a warm tint. There's a last run in a special edition that Tony's referring to right now off the muyshondt site. I have a CRI Preon 1 as my one and only (before that was a Photon as my first serious light) and have a Aeon MKII coming, very excited, my first high end flashlight.

    Yes, CRI and moonlight were the reasons why I dropped the big bucks on the Aeon. It's CRI *and* neutral too! Heavenly. The Preon 1 CRI is a bit too yellow for me.

    Am I crazy for contemplating buying insurance on my Aeon MkII? I don't know what I'd do if I lost it. I'd insure for $1k cus that's about the amount I'd have to spend to find a replacement.

    Tony, does you Aeon collection have a price tag? (hypothetical of course).

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  4. If you can't tell, I insist on CRI. I waited on a light that was going out of production that I otherwise wanted and wouldn't get it until it was CRI.

    Most people I know would be willing to pay extra for 'easier on the eyes' lighting for their desk or room but something short-circuits when it comes to flashlights, I don't know.

    In short: Agreed.

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  5. Tony, your illustration for this post is revelatory! For most people for the blackout-emergency, any light is still better than none, but I am going to have to get myself one of these true-color lights just for the quality of it. Thanks for the thorough presentation.
    Bill

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  6. Testify! Nice post. I am already a convert to neutrals (favorite neutral beam: Foursevens Mini-X 123 neutral XM-L) and suspect I would love high CRI. I really wish I had wised up about my preferences in time to snag one of the Hi CRI Mini CR2s (Mini MLR2s, whatever), what an amazing keychain light that would be.

    Anyway, I ordered the Terralux penlight that you recommended above and am looking forward to trying it out. If it's good to go I think I will gift it to the wife as a glove compartment light. Cheers!

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  7. I'm interested in a Haiku for EDC use. Don doesn't offer the XM-L (most popular) at the moment, but he said he has both the Haiku with a Nichia 119 which he drives at 500 mA on high or a 119V Nichia High CRI which he drive at 660 mA. I'm buying into your Hi CRI thoughts, but having never handled one, I don't know if they would suit more general uses. Don mentioned that the XM-L puts out about twice as much light as the 119, but the 119V would put out a little more. If you could only have one light for ECD would it be the 119V or the XM-L version of the Haiku?

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  8. Sorry, Don certainly does offer the XM-L (I misspoke earlier).

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