The CREE "Angular-Tint-Shift" flaw syndrome..It's causing brain damage.

nottawhackjob · 2018-05-01T13:32:47.000Z

Has anyone tried camera-type lens filters to see if a noticeable improvement can be detected?

Just wondering if it would be possible to correct these tint aberrations without affecting the original characteristics of the beam such as throw, spill, etc.

I’m also implying as well/tangentially that if AR glass is used is there any noticeable change to these tint aberrations vs a bare dome?

The_Driver1 · 2018-05-01T13:35:49.000Z

nottawhackjob:

Has anyone tried camera-type lens filters to see if a noticeable improvement can be detected?

Just wondering if it would be possible to correct these tint aberrations without affecting the original characteristics of the beam such as throw, spill, etc.

I’m also implying as well/tangentially that if AR glass is used is there any noticeable change to these tint aberrations vs a bare dome?

A filter glass would always alter all the parts of the beam, so also the good parts.

maukka · 2018-05-01T13:51:42.000Z

You could put a round filter (and a diffuser if necessary) on the center of the lens to only correct the spill/corona. Adjust size to fine tune.

Also totally not worth it, when you can just swap the emitter.

ma_tumba · 2018-05-01T14:17:39.000Z

This is what I did. Problem solved but maukka is quite right. Just too much trouble.link

maukka · 2018-05-01T14:20:12.000Z

That modification of the hotspot+corona with a ring that sits under the bezel is certainly easier to install. Good thinking.

ma_tumba · 2018-05-01T14:31:45.000Z

And this is my new grail. A mule with a zero tint shift. Just beautiful pure sunlight (kudos to Clemence, Tana, djozz) link

DBSAR · 2018-05-01T16:10:55.000Z

djozz:

It appears to be difficult to get it right. Even Nichia has not really mastered it, the 144A has big tint shift problems caused (at least partly) by an uneven phosfor layer, giving an ‘egg-yolk’ problem in the beam. Egg-yolks also appear in some XP-L Hi beams, varying with individual leds, which is weird because you can not see looking at the led what is causing it.

The best beams I have seen in current leds are from the 219B, Luxeon V and LH351D. And with the trophy going to the E21A, a difficult led in use but when you got it working and centered: :heart_eyes:

I forgot to mention that most higher grade SMD LEDs don’t have the angular tint shift issue, (probably because of the flat embedded die design of them, but they don’t make good LEDs for reflectors is a drawback.

DBSAR · 2018-05-01T16:12:33.000Z

KawiBoy1428:

That is why the only Cree LED’s I prefer are the XP-L HI and XHP35 HI, they seem to be the cleanest.

Same here, I have swapped in many XP-L HI emitters in lights i use.

gchart · 2018-05-01T16:13:42.000Z

I have really liked the LH351D’s lately. Swapped those into some of my recent lights… very nice beam.

DBSAR · 2018-05-01T16:28:38.000Z

gchart:

I have really liked the LH351D’s lately. Swapped those into some of my recent lights… very nice beam.

I hope to check those out soon. ( have not tried any yet.

stephenk · 2018-05-01T21:17:51.000Z

At the end of the day, if the tint shift is not an issue for Cree’s main market (which is not flashlights), then I doubt they’ll change.

Ronin42 · 2018-05-01T21:59:30.000Z

+1

Have always liked the MT-G2

I think we all should boycott all Cree Leds (except for the MT-G2) (That will send our message!!!)

Or will they even notice?

ToyKeeper · 2018-05-01T22:30:07.000Z

I’m still hoping for XP-L HI in the FW3A, but with a frosted optic other emitters look okay too. And other emitters cost less.

BlueSwordM · 2018-05-01T22:33:34.000Z

I’ll just buy a FW3A, and swap it Samsung LH351Ds in it.

I’d love if Lumintop provided the option directly though.

djozz · 2018-05-01T23:02:50.000Z

I have checked the 4000K 90CRI Samsung LH351D in three hosts now, a Sofirn SP33 with 30mm smooth reflector, an S2+ which I checked with both smooth and OP reflector, and a E2L with triple narrow Carclo TIR.

In the Carclo I found the led a bit over-floody, with better beam than the XP-L Hi but not flawless.

In the 30mm smooth reflector the beam is really nice.

In the S2+ I could not use the smooth reflector because the beam was ringy with a couple of tint variations (yellow-ish in the hotspot and corona, rosy in the spill). At least the rings were way less visible when shifted to an OP reflector, the beam is now agreeable.

Regardless of which host it is in, this led has the best tint when over a couple of amps. Below 1A the tint has less red and more green (the Luxeon V shows the same phenomenon)

So if a high CRI led is an option for the FW3A I’m not in favor of this led, I prefer Nichia 219C’s even though the output and efficiency is a bit less: better beam in a TIR, more pronounced hotspot and no hint of green when run on the single 7135.

ToyKeeper · 2018-05-02T08:32:55.000Z

I’ve been trying to put together a poll for FW3A emitter type. Djozz, do you think LH351D should be on the list?

My favorite options are XP-L HI and Nichia 219c high-CRI, but there’s also XP-G3. And maybe XP-G3 high-CRI. And maybe XP-G2. And maybe Samsung LH351D.

The rainbow effect may not be a huge deal on this host because of the 10511 optic, but it would be very noticeable when using a 10507 optic. The 10507 makes everything look bad.

djozz · 2018-05-02T08:52:33.000Z

I think a few more people should report their findings on the LH351D, but some will like the big flood combined with good output, so yes, put it on the list.

dhvl1357 · 2018-05-02T14:16:29.000Z

This is what we camera nuts call purple fringing, I guess. When white light is refracted, the blue/indigo/violet parts get thrown towards the periphery causing this. It’s really expensive and difficult to correct this in camera lenses so I do believe it would be a real challenge in LEDs, especially neutral and cool white ones.

BlueSwordM · 2018-05-02T14:19:38.000Z

I personally vote for the LH351D.

Not only is it a great emitter, its cost and efficiency are excellent for a 3.5mmx3.5mm emitter.

Nicolaas · 2018-05-02T14:43:41.000Z

KawiBoy1428:

That is why the only Cree LED’s I prefer are the XP-L HI and XHP35 HI, they seem to be the cleanest.

Well exactly. Yhe HI versions of Cree emitters have the lowest coronal discoloration and the most even tint in both spot and spill.
Too bad the buggers have such high Vf.

This is also why I think that the Cree HI leds are not only very well suited to throwers, but to all types of lights.
You get a little lower output but much higher quality light.
I especially like the XP-L HI V3 3C, beautiful tint with a good amount of red (to my eyes that is).

Still, I like the Nichia NW the best.

Grtz
Nico