Debunking that Low CRI is brighter than High CRI... not necessarily

CRI does cost lumens

but in this case, it did not cost Lux

The High CRI sw45k with less Lumens, ended up having more Lux than the Low CRI xml that has more lumens…

I think thats really cool!

next time somebody tells me they want the most lumens possible, and therefore do not want High CRI, I may be able to show the High CRI option actually has more LUX

I dont think most people have been exposed to Lux Education enough to understand it, yet.

This is my attempt to spread an understanding of LUX in order to dispell the Myth, that a Low CRI LED will be brighter on target, than a High CRI LED… not necessarily… and not in the example I posted above

part of the problem is Lux and throw specs are not always part of the factors that a buyer considers… sometimes only Lumens are considered when choosing a light

the typical assumption is that more Lumens means more Throw… but that depends on the size of the hotspot

maybe this will help too

yes
unfortunately, there are no specs listed when I modify the light to a different LED

I see you discovered the difference between “lumens” and “throw” jon_slider. :student:

One other way to consider the difference is a simple test you can do with different lights.

  • To compare the lumens of two different lights - go into a bathroom and close the door. Hold one light in each hand. Tilt your head down and look at something on the floor near your feet. Hold one light above your head and point it at the ceiling and turn it on. Then turn it off and repeat with the other light all while keeping your eyes on the object on the floor.

The trick with this test is the hotspot of each light is not in your field of vision at all. Instead, all you see is diffuse reflected light that bounced around the room and got to the object around your feet. If one light makes that object light up noticeably more, it probably has higher lumens. Note however, for the difference to be visually noticeable there typically needs to be at least a 20% difference in lumen output.

  • To compare the lux (throw) of two different lights - point each light at the nearest wall and compare the hotspots. The one with a more intense (brighter) center of the hotspot has better throw. To get a better idea of which one has more throw, try pointing your lights at a dark object. Or just wait until night and point it out the window at something off in the distance.

Note also modding to high-CRI doesn’t necessarily mean you get more throw. In the case of your old RRT-01 with XML vs. Nichia 219B SW45K… yes, the Nichia has more throw. But in many cases low-CRI leds have more throw. For example the following low-CRI 3v LEDs all easily outhrow SW45K: SST-20 5000K, XPL HI, and Oslon White 1 or 2.

yes, and
its more than that

I discovered that High CRI can have more throw than Low CRI

yes
that is what I did… I put the sensor of my light meter in the middle of each hotspot, on the wall

I show the results of that measurement in the photos in the first post

the High CRI LED with less lumens has a smaller brighter hotspot, than the LED with more lumens

I get to have cake and eat it too
high CRI and a Brighter hotspot

next time somebody tells me they want to keep the Low CRI LED because it has more lumens… Im going to show them the High CRI can have a brighter hotspot.

beam size matters

ToyKeeper just pointed out that the hotspot of a single LED is five times brighter on target than a triple LED.

the reason for this is that the single LED is producing a more focused hotspot. Whereas a triple spreads the lumens out over a wider area.

this is about how much more brightly the target is illuminated by a small tight beam from a single LED, and how much wider, but dimmer the illuminated area is when using a triple.

The single LED is brighter on target because the light is focused into a smaller area. The triple makes more total lumens, but spreads them out over a larger area, so the brightness on target is lower.

I found an off the shelf example,

thanks for your help pointing out that the difference between Total Lumens out the front, and Lux on target,

can be found on the packaging of stock lights:

Tighter beam pattern doesn’t mean more lumens or more otf, it’s more throw. Thats why am LEP flashlight at 500 lumens can out throw the 32000 lumen flashlight. Tightness of hotspot, vs spill and flood

Smaller emitter will always win in the same size reflector, use two of the same size emitters in different tints is the only way to run your test.
I feel trolled by this post

Brightness was one of the reasons I used a SST-20 in the Fitorch P25. Got rid of ugly tint and gained some beam distance. I love it when a plan comes together.

me too!
I figured out how to get High CRI with more throw, than Low CRI that has more Lumens but less throw

another example of more lumens with less throw
the difference is due to the size of the hotspot:

:slight_smile:

have I managed to explain in a way you can understand now?

[quote=Firelight2]

It's not the thickness of the phosphor layer (alone). High CRI LEDs feature completely different phosphor mixtures to achieve that better light quality.

Your explanation is clear, but the topic of the thread causes confusion:

Here’s why:

  • When we hear the term “brighter” we think of lumens. Your example in the original post is wrong: SW45K is not brighter than XML. The XML produces more lumens (around 500) compared to the SW45K (maybe 250).
  • The “lumens versus lux” debate is something most of us are familiar with. As flashaholics we know that lumens is not necessarily correlated to throw. Throw is mostly governed by the intensity of the emitter and width of the head. Usually small intense LEDs like Osram White 1 in single-emitter setups with huge wide heads give the best throw. In contrast, for the most lumens you generally want lots of LED die surface area. Typically this means using large LEDs like XHP 70 or XBT 90, or multi-LED setups.
  • CRI is a separate issue…. it’s not part of the “lumens versus lux” debate at all. Most high-CRI LEDs produce less lumens and/or throw than available lower-CRI alternatives for the same light, but that’s not a hard and fast rule.

A better title might have been “I was surprised that my high-CRI LED had more throw than the original low-CRI LED”

Congratulations, you just “discovered” the concept of Lux. Intro to Light 101, 2nd day. Tomorrow, CCT! :student:

Throw != brightness

I agree word-for-word with every single thing Firelight2 has said.

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edit: I see I even used the same verbiage as Firelight2 used in post #15, I swear I didn’t do that on purpose, lol.

Around the house, I normally just grab my WW Xeno E03 (to distinguish it from the 40 other “E03”s out there) with diffusion film on front glass. Great smooooth wall of WW light, perfect for poking around down the basement without having to turn on all the lights in existence.

T’other day, I forgot where I put it, so grabbed my GTmicro to go down there. Ugh, it was nigh useless, even cranking it up to stoopit-bright. Intense hotspot, could’ve used a laser-pointer for what good it did me. Everything else was dark, washed out by the blinding-bright hotspot. And dark-brown paneling all over (even the ceiling; it is a basement, after all), so I couldn’t even use ceiling-bounce for light.

“Bright” ain’t all it’s cracked up to be. Just use the right tool for the job.

So yes if I can get hi cri that out throws a cool white emitter in the same form factor (host) yes I’ll go hi cri almost every time.

A lot of hair splitting here. I perceive a spot of high luminance as bright.

I think it’s clear what Jon means. No?

thank you all for helping me to learn how to communicate more clearly

the brighter smaller hotspot on the right:

is not from the light with more total lumens out the front,

and it is also not from the light with more emitters

the light with more Total lumens out the front, and more emitters,
is not more efficient at producing a bright hotspot

because the extra lumens and extra emitters create a larger, dimmer hotspot, the triple needs to use more battery power to match the brightness of the smaller, more power efficient, and brighter on target, hotspot.

So Im debunking three myths

  1. with more lumens I can see farther outdoors
  2. triples are more efficient than singles, at letting me see farther outdoors
  3. Low CRI is going to be brighter on target than High CRI

what is actually true is

  1. smaller hotspots let me see farther than larger hotspots do
  2. single LED lights use less battery power, to let me see farther, than multi LED lights
  3. The Low CRI xml in my stock RRT-01m produces a larger hotspot, which is not brighter on target, than the HIGH CRI sw45k in my modded RRT-01, that has a smaller hotspot

So, I think I might buy an FW1a with High CRI and less lumens, instead of an FW3a or D4 with Low CRI and More Lumens,

So I can enjoy an efficient, small, bright, High CRI hotspot…

and instead of focusing on the Lumens specs…

I will focus on the throw specs :+1:

1. Who ever thought that just because a light has more lumens that it would throw farther?
2. Triples are more efficient, and again, there was never a claim that they throw farther (in fact, the opposite has almost always been the rule).
3. * CRI has nothing to do with the brightness of the hotspot.*

Why are we still discussing the fact that a light with a smaller hotspot will also have a brighter hotspot, when other factors are close to similar? Yes, even if a light has more lumens, the center of its beam may not be as concentrated as a light with less lumens. My Convoy C8+ with an xp-l hi, putting out 1100 lumens is far brighter on a point than my Lumintop EDC18 with three of the same LEDs, putting out 2800 lumens. But the C8+ is nowhere near as useful or versatile. Rarely do I need such a bright spotlight that can throw as far as the C8+ (I call it the dog finder, for when my min pin escapes from the yard). If I wanted to use it on its lowest setting indoors, I’d be constantly sweeping the light back and forth to see things in that tiny spot. Regardless of whether I need a floodlight or a spotlight, the lower CRI LEDs will more likely have more output than high CRI LEDs in the same setup. That sacrifice of power for color rendering is always a consideration in any light, just like one’s preference or need for flood vs. spot. Please stop comparing, combining, and confusing the two.

Very good points, Jon_Slider. It’s about picking the right tool for the job.

For seeing off in the distance a light with a small hotspot is great. I have an Eagtac T25C that I modded with an Oslon White 1 and a FET driver. Throw on a 16340 is amazing for such a tiny light. But up-close I find it largely useless. The hotspot is tiny and so blindingly bright it washes out the spill. And due to the deep reflector the spill is quite narrow.

For a pocket EDC that is used mostly at close-range small triples and quads work great. their wide even hotspot is excellent for lighting up a large area up close, and with a FET driver and good cell they have enough power to punch out a fair distance just through brute force … but without that kind of high output driver they’re much less impressive.

I get what you’re saying about triples though. For years my Jetbeam TCR-01 was setup as a triple XPL HI. I wasn’t EDC’ing it though, because the output didn’t really satisfy. Overall output seemed quite low, probably because I was used to FET drivers and larger batteries in my FW3 and D4 series lights.

I recently refurbished my TCR-01 by converting it back to single-emitter with an OP reflector …… much better. The hotspot gives it respectable throw and the spill is bright and wide enough to be useful. Overall an improvement compared to when I had the light setup as a triple.

CRI? … If I can get high-CRI without sacrificing lumens, throw or tint it’s always better than low-CRI. My 2020 RRT-01 was greatly improved by replacing the stock 70 CRI 219C with a 90 CRI 219C salvaged from an EDC18.

similar personal preference
I use my TCR-1 with sw45k as EDC more often than my RRT-01 with triple sw45k.

I find the triple less useful for general EDC and it gets carried less. It also seems dimmer on target, unless I turn it up to a much higher total output level, which consumes batteries faster.

otoh, the triple is more useful when I want to use it as a light source for a photo…

the single in the TCR-1 battles with my camera light sensor, and I cant get an evenly lit photo.

Why do they say don't look at an eclipse ?

Is an eclipsed light brighter than the reflection of the entire moon ?

A smaller hotspot is just more intense and reflected off a white wall people will call it brighter .but go outside and logically ask yourself if a Jacob A60 putting out 150 lumens is brighter than a Emmisar D4 and you really can't make the argument .

one is lighting up your neighbors hubcap 300 feet away while the other lights up your entire yard .

it's a question of semantics or incorrect terminology

Which end of a screwdriver would you rather be hit in the eye with?

When shooting light into a sphere to test the amount of lumens you have to diffuse the light / bounce it around a sphere or a plumbing tube before taking readings with your meter .

One is a measure of brightness vs a measure of intensity. How you feel about them or react to them isn't really very important to what they actually are .//facts don't care about your feelings.

Higher lux has always confused people when discussing brightness ...A cheap laser will shoot miles ... it's shooting a bullet vs catapulting a cow.

High Cri is just making light shine on the world like God originally made it.. Good

I think this may be the key point, lol.

The anal-retentive among us (I’m totally guilty!) tend to get testy when we see words (especially technical terms) being used abnormally/incorrectly, even when we (kind of) think we understand your intent.

:beer: