Olight Thrunite Maratac Prometheus Color and CRI explorations

My first Vinh order.

This is my story about my aaa flashlight experience, as a total newbie, and some of the stages of my journey. The result of which is a request to modify a PWM 5800K XP-G2 Maratac Cu, to high CRI with No PWM.

Today I mailed my Maratac Cu Rev 3, whose PWM mode sequence is 40-1.5-138
and an Olight i3s, whose Current Controlled mode sequence is 20-85-0.5

I requested that the Olight Driver be installed in the Maratac, with an LED swap to N219A

Backstories
Tint and CRI
I have been extremely fortunate to have the help of darksucks.com owner and creator of the Prometheus Beta Cu that I recently bought. Its mode sequence is 1-15-85 and it has transformed my awareness of LED Color Temperature and Color Rendering Index.

When I picked up my Beta Cu, in person because I live nearby, I asked Jason to take a reading of the CRI of the light, along with several other lights I had brought with me.

When I realized how little red and what low amplitude of most colors was present in my Thrunite Titanium with XP-L, Olight i3s with XP-G2, and Maratac Rev 3 also with XP-G2, it was a revelation. The result of which is my current "Copper Dream Light".

The goals of my Dream Light are a quick release keychain light powered by a single aaa for:
1. Use as a nightlight
2. Use during the day, illuminating under a car, under a bed or couch, where there is ambient light
3. Use while Van camping, to illuminate things in my hads while sitting inside a Camper, and to wear as a headlamp on a baseball cap when moving around outside cooking something on a charcoal grill at night, with no ambient light, away from the city.

I want high saturation of color, rich reds, yellows and oranges. No green tint, nor blue. So I chose the N219A. I actually only have one each of a N219A and B, and they are quite different. When shining them on a red object, the A has a redder red. The B has by comprison a slightly cooler, bluer tint. I prefer the A, even though the B is brighter. I am not prioritizing throw, in fact I am more interested in a broad flood to light just the space of a single room, not trying to spot things more than 10 feet away.

The Maratac Cu has a number of features I find fascinating, despite being heavy. It also has a reversible pocket clip, that has proven very useful as a quick release keychain light.

For nightlight, I wanted less than 1 lumen, but for seeing things in my hands in full darkness, I wanted more than 0.1 lumens. For those reasons, I chose the 0.5 lumen driver of the Olight to transplant to the Maratac head of the Dream Light

The lights I have mentioned have lows of 0.04, 0.5, 1, and 1.5, so I felt able to prioritize my low light level preference after using those lights. Of the four lights Im discussing two have PWM circuits, both are copper, and I want to leave PWM behind. I plan to modify both lights, but am doing them one at a time. The Beta is more likely to receive the driver from a Thrunite Ti3, whose levels are .04-12-120.

The beauty of the Maratac body is that it works with both its own head, or the Beta head, which means I will get to mix and match if I decide I want to carry a L-M-H or a M-H-L Cu light, with either a 0.04 or a 0.5 low. (Truth is I will carry both, lol)

The Olight i3s and Maratac Rev3 use XP-G2 emitters, the Thrunite Titanium has an XP-L, and the Prometheus Beta has a Nichia 219a

Pictures:

the four lights

the four beams

the three LED tint reflections

The color graphs Jason so kindly allowed me obtain (this is hugely important to me, to have actual color temperature and CRI information, not specs, not guesses, not vague descriptions, just the numerical facts):

i3s 6000K CRI 71

Ti Ti 5700K CRI 70

Maratac 5800K CRI 70

Prometheus Beta 4400 CRI 87

for further exploration about CRI including comparisons of N219a and N219b see this very informative thread
http://budgetlightforum.com/node/27652?page=1
"the higher the current through 219A the higher the CRI, not only visible but measured as well. Although it is maybe 5 CRI range of change if I remember"

http://budgetlightforum.com/node/27652?page=2
"Long, Med and Short wavelength sensitive cones .

They found a massive difference between two subjects, both with apparently normal colour vision. Subject one 'JW' had 75.8% Red cones, 20% Green and 4.2% Blue, while subject two 'AN' had 50.6% Red cones, 44.2% Green and 5.2% Blue…

So there is likely a lot of individual variance as well, whilst to some 4000k might look like 'pure white', to others 6000k might look like 'pure white' in similar conditions. You have to find your own general preference and look for that, mine is generally around 5000k i.e 3D/4A."

Thank you for such an eye opening post. Will read the whole story on blf

Thanks for good info.

Very informative..thanks.

thanks for the kind words
a few more observations about Tint (CCT) preferences.
My preference in Tint changes based on background lighting Tint.

for example, here is a photo of my kitchen at night, using a 3000k Warm White light bulb as background, and two of my flashlights, the left one is a Warm White 3000K XPG (similar to sunlight on the horizon at sunset), the right one is a Cool White 6000k XPG2 (photos are iPhone, automatic white balance). Notice the 6000K beam looks sort of blueish. I would not choose it for use in the evening, its too harsh and glaring.


next is the same scenario, but the background house light is at 6000K. Note the Cool White 6000k beam on the right no longer "looks" blueish. Instead the 3000K beam on the left now looks more orange than the walls. I would choose to use the 6000K flashlight when the background lighting tint that my brain is living with, is 6000K (as happens during the middle of the day in sunlight)


So, Tint preference depends on what the ambient light Tint (CCT) is at the time. In Warm ambient light, a Warm flashlight is a better match than a Cool White one, imo.

otoh, in Cool White ambient light, a Cool White flashlight is a better match to the white balance in my brain.

So if we consider 3 ambient lighting scenarios, Warm (3000k), Neutral (4500k), and Cool (6000K), there will be an LED that most closely matches the environment at that time, with a similarly Warm, Neutral, or Cool tint.

For these reasons, I have developed a selection of 3 different flashlights, that I use at different times of day (and different background Tint).
1. When it is late at night and the backgound lighting is Warm, I choose a 3000K tint. That includes waking up in the dark to use the bathroom.
2. Earlier in the evening when indoor light is Neutral, such as preparing dinner, I will prefer a 4500K tint.
3. During the day, when sunlight is Cool White (6000K), such as looking under the hood of a car, I will prefer a 6000K tint.

so when people say they have a favorite tint, to understand their choice better, I would ask what is the background lighting tint they are using the light in. I think we would find that people working on a car during the day will not like Warm tint, they will prefer Cool. otoh, when Im in a mellow mood, possibly even with candle light (2000K), and am using low brightness levels, I will prefer a flashlight with a Warm tint, and at a lower lumen level.

tint "preference" depends on the ambient White Balance of the Brain at the time.

Now about CRI. Working on a car, Cool tint is preferred, and unfortunately, that will also be Low CRI, due to the nature of LEDs

however, in the evening preparing food, cutting carrots, tomatoes, bell peppers, and other colorfull foods, I will want a High CRI light source, so I can see the Reds in a more natural looking tint that is not too blueish or purpleish..

here is some red tandoori chicken. The piece on the left is lit by a 6000K flashlight, the one on the right is lit by my Neutral White High CRI Nichia 219B.. can you see how much redder the piece on the right looks.. Thats because High CRI shows reds better


Since there is no One Tint that matches all 3 different ambient Tints, If I only had one to choose, I would pick the N219 at 4000K. It makes food look right, even though its a bit too orange for working on a car during the day, and a bit too blueish to use for a walk to the bathroom in the middle of the night.

Here is an example of the 3 different LED tints Ive been using as a reference




The first two are factory stock lights, the far right has a custom LED swap (few lights I know of come with a 3000K LED from the factory)

Now to explore Brightness (Lumens) preferences. Basically, I seek to use a flashlight that is at least as bright, or brighter, than the enviroment background lighting. So during the day, I prefer higher brightness, above 100 lumens. In the evening I prefer medium, between 20-40 lumens, and in pitch dark, I will tend to prefer lower brightness, below 5 lumens. In fact, for a bathroom light I find 0.5 to 1 lumen is plenty bright without being too blinding.

so looking at those 3 flashlights in the above picture, I would mostly use the Cool on High, the Neutral on Medium, and the Warm on Low.

Im considering a customized flashlight that does all that, using 3 separate LEDs, each tied to a different brightness, like this
XPG 3000K @ 1 lumen
N219 4500K @ 30 lumens
XPG2 6000K @ 150 lumens

I do think that our brain likes warmer tints at lower brightness levels, and cooler tints at high brightness levels. It also happens that Cool LEDs will be the brightest. Whereas LEDs that are Warm, are also less bright. Because LEDs are naturally good at making blue light, to get them to produce reds requires a phosphor coating that blocks some of the light, while also producing more red spectrum light.

Redder and Dimmer go together in Warm light
Bluer and Brighter go together in Cool light
and the N219 falls right in the middle, its Warmer than Cool, but Cooler than Warm, while still producing LOTS of red. A light that produces reds, will reflect more red off something being illuminated. For example, a Nichia will work well to check the steak on the BBQ, but a Cool LED will make it look too purple, and wont really help reveal how much red is left, how cooked the meat is.

One last example, note how a low CRI Cool LED makes my hand look pale and dead (because it produces too little red)
then see how a High CRI Warm LED makes my hand look a more natural color (maybe even too red, which is where the Neutral Nichia 219a or 219b becomes a good compromise)