Interesting optics thread

Fenix E16 is known for its unique flat optics. This kind of optics is called RXI and quite popular in literature but nearly completely absent from the market. It seems to stifled by patents.

I found 2 makers that manufacture such optics. Neither looks like the Fenix one so there are surely more.

GR Optics has a family of COB lenses from 35 mm to 91 mm

Light Prescriptions Innovators makes a 41 mm lens:

Soraa uses RXI in their bulbs:
https://www.archlighting.com/technology/leds-understanding-optical-performance_o

Some paper that I liked, they fold light path RXI-style with refraction alone:

It’s the same as this, just worse.

And it’s called a catadioptric.

Oh, I forgot that lens. It seems to indeed use the same working principle. Except that Carclo has really low transmission, I suppose it spills light everywhere. That’s not the case with metallized reflector lenses.

The Fenix looks more like a hybrid reflector than a catadioptric. The hybrid reflector has a TIR that directs the light from the LED into the reflector. Polymer Optics makea then with aluminum reflector and plastic TIR. Auer in Germany makes them out of glass.

It doesn’t look so to me.
First, it seems to have a small metallized ring at the front that I can’t explain otherwise than “it directs light towards the main reflector”.

Second - it’s just too flat and angles don’t seem to add up. I think it would generate extremely wide beam with light hitting the side reflector directly. And we know that it actually collimates fine. Not neearly as well as a TIR in Olight S1 Mini but the output is nevertheless quite throwy.

Hard to tell from the pic, it could be just a reflection of the reflector surface too. But I don’t have access to one so I defer to the guys that do…

Fraen makes a cool optic for COBs; nested multi TIR which supposedly reduces spill. Would be great if they made them for COBs larger than 22mm.

I do have these cool hybrid reflectors from Auer, and aside from working well, are quite beautiful to look at in person:

The catadioptric is literally the same thing, a hybrid tir+reflector with a metallic coating on the rear side and the center which reflects the light coming at incidence angles too large for total internal reflection. That’s what allows the optic to be so flat.
Go look up the carclo 10158 on google and you will see it works in exactly the same way.
I own 4 of them.

I have a couple of the 10158 in my possession as well. They basically work like the old telephoto lenses for cameras - which were great because they gave you a lot of zoom in a more compact lighter package. But you needed either a good tripod or nerves of steel to keep your hands steady.

The hybrid reflectors from Auer, Polymer Optics, and Fraen each work in a somewhat different way. The Auer seems to be a combination reflector/side-emitting TIR, the Polymer Optics seems to be just a standard reflector with a typical TIR mounted on the center, and Fraen uses what they call a nested lens. I have a couple of the 110mm narrow spot Auer Jupiter reflectors as well, and they’re a work of art even more so than an optic. Have not obtained the Fraen nested TIR yet. I do have the Polymer Optics hybrid reflectors, but they are rather small, 30mm reflectors. I do plan on retrofitting them on some cheapie hosts to see how they perform.

The links agro posted, including that fenix flashlight, work on the exact same principle.
A metallic coated center reflects light that wouldn’t get reflected by TIR and the glass/plastic at larger angles TIRs the light back down into a reflective-coated surface to bounce it forward.

Yes I know that. I was merely pointing out that 1) there were more than one way to skin the proverbial cat, and 2) it didn’t seem obvious to me that Fenix does indeed have some kind of reflective coated ring pointed toward the LED. I can’t determine the depth of the reflector or the angles or such as Agro pointed out based on a head-on view or even the pics in Fenix’ website. I think it’s cool nonetheless.

Enderman, you probably know this, what does a smooth low angle TIR look like under an aspheric and catadioptric lens?

Your question is not very clear, but if I under stood it correctly you can’t put any kind of TIR under the 10158 catadioptric.
The 10158 has a small opening in the bottom that fits an LED, it is not like a lens where light goes through the whole thing.
Light enters it from a small hole and then it gets reflected/refracted forwards.

If you put the 10158 under an aspheric lens it will make a large ugly looking circle on the wall as the lens projects the front image of the 10158 which is hundreds of times bigger than an LED die.

Maybe….

Fraen makes a cool optic for COBs; nested multi TIR which supposedly reduces spill. Would be great if they made them for COBs larger than 22mm.

I do have these cool hybrid reflectors from Auer, and aside from working well, are quite beautiful to look at in person:

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I thought it used TIR and not metallization. Thanks for setting me straight.
So…it’s the best documented lens of this type and is clearly a poor performer. :frowning:

I thought it used TIR and not metallization. Thanks for setting me straight.
So…it’s the best documented lens of this type and is clearly a poor performer. :frowning:
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It does use TIR but not in the conventional way. The light rays bounce off the top lens surface. The area in the center where the angle of incidence is too great for the TIR effect gets a reflective coating.

OK, I think I finally have the full picture.

I think it works well, though as you could probably imagine it works better for certain emitters…. STO uses a similar if not the same lens on one of their lights.

You mean Eye of Sekhmet? Could that be 10158? Size seems to roughtly match.

BTW, I found another maker. Darkoo.

here

Here’s a very interesting LED/compound parabolic reflector setup! I think this would be a cool setup for a handheld; if you wanted a good mix of spill and throw… Can’t find a pic of the beam however.

https://www.illumi-vation.com/product-page/mooney-m20-c-d-e-f-g-j-led-landing-light

i may be out of date in my thinking here but…

car headlights, they used to have ‘fresnal’ type patterning, but it wasn’t to aid the overall throw, it was to even out the beam to get rid of dark rings and likes, or to ‘widen’ the beam, in eather case it makes the lens brighter to look at and reduces the overall throw. (bare in mind the tail end of throw is a pitiful amount, even if it reach’s the moon you wouldn’t notice it, so it would be better spent being spread into the usable beam).

the one thing i have noticed about focusing lenses is they do turn into a cinema projection, but mostly they cut out the spill, i’ve only played with a dozen or so torch’s but the one thing that was blattent was theres more throw with unlensed, e.g. i got a couple ‘throwers’ with massive focussing lenses on, now whilst i was actually impressed by the apparent throw, an el cheepo bike light with an old T-6 in it out threw them all, all be it with half a field worth of side spill. (no magnifying, just a standard non coated crappy face plate lens).

to further my thinking, i have a red led with a focusing lens i used for wild life, simply because there is next to zero side spill, quite literally a tight square led projection arriving un announced at the other end…but, again, the el cheepo dish out throws it with heck of a lot of side spill.

the reflector shape seems to have more effect.

just a thought there…at the end of the day there’s the rules of thumb, and then when you try you see it was the other thumb.