Aspheric + secondary optics

I believe the STO Storm of Ra has a TIR/aspheric combimation…

edit: Guh, I somehow missed this was already mentioned up top

The Chauvet Q-Spot 260 used a Luminus CBT-90 (or CST-90) and two lenses in an adjustable-focus design. I always wanted to get one of these and pop a CFT-90 in there as it’s capable of driving the LED at 27A max… Then swap the lenses out to make it a mega-thrower (if I remember correctly the original literature had a 1M candela rating!)

There is another flashlight brand,named MTE,which makes pencil beam lights using optics. http://www.mte-led.com/product.asp
Demo MTE H8-2 Optical Lense Torch Spotlight Circular Beam 500 meter range Flashlight Demonstration - YouTube
MTE H8-1s MSITC Edition XM-L2 1200 Lumen max. - www.msitc-shop.com - YouTube
MTE H8-1s - YouTube.

One thing that might have been obvious to some just appeared in my head.
There might be others who haven’t noticed as well so I’ll share it.

Zoomies tend to be hard to waterproof because they change volume while zooming. They can’t be air-tight so they are hard to make water-tight.
Separating the head into 2 compartments, one tight and the other not, would enable good waterproofing. Maybe not something that would result in great beam underwater but at least it would prevent damage.

This is quite natural to do with a dual-lens zoomie as long as the first lens doesn’t move. Like with Xiaomi FZ101.
Therefore a dual lens zoomie can fairly easily overcome one of the major drawbacks of zoomies.
Note that the first lens might be a regular projection lens or a TIR sealing it is just the same job.

The solution would be to have the optics move inside a completely sealed body. Bonus points for filling the entire chamber with an inert gas like nitrogen :money_mouth_face:

It can be done, in 2 ways:

  • move the lens inside, keep the one outside fixed
    • I believe it was considered on BLF - and rejected for some reason. Bad beam I think
    • also - zooming itself is hard. Servo motors? Magnetism? Complexity.
  • build a chamber around the regular zoomie head
    • increases size
    • adds the same complexity to zooming

Therefore I believe that a sealed chamber inside is a better option for general-purpose lights.
High-end or diving might be different.

Or, just put your flashlight in a ZipLok bag. A heluva lot cheaper. And you can find them in virtually any supermarket. But in terms of:

That’s quite simple. A thumb screw is easily sealable, and that can be attached either to a screw, or pinion that engages with a gear rack.

Not sure what your application is. If you just need rain resistance, even a regular zoomie would be mostly fine If you’re trying to make a diving zoomie then I don’t think you have much of a choice but make the entire optics system contained and adjustable in the body, otherwise you’d reach a depth where the zoomie head would be inoperable or possibly catastrophically fail because of pressure.

If the light is big enough, one might be able to fit a pressure equalization valve somewhere. (See Pelican cases - it’s a GoreTex membrane basically.)

There is also intermediate step - kayaking. Putting the light under water is a part of the sport but it doesn’t have to work there well. And extreme depths are not required.
Zip bag works there…and is used a for many things…but a waterproof light is just more convenient.
But more importantly - this matters to other users. Because it enables rating the light as IPX8 as opposed to IPX6. This difference means a lot to many of those who simply want “good” w/out having specific waterproofing needs.

Interesting. I remeber seeing such discussion but w/out a successful solution. Maybe it’s just my memory or maybe you can immediately find solutions that are hard to BLFers. :+1:

Methinks it’s rather simple… Same principle as a gate valve you have in the water mains - a sealed post. From there, what ever means you desire to convert rotary motion to linear is possible. The ratings of the seals would determine how far you could submerge the light as the pressure would multiply as you go further down. I would guess you’d need heavier gage walls for the battery components. I am not versed enough in battery technology to know what effects that would have on batteries.

Initially when I read this post I thought that fitting a valve on a light would take a lot of space.
But later…I got a different vision.
To describe it, let me start with SK68. It is applicable to many different designs but it’s relatively easy to explain with such starting point.
So…SK68. It has a number of fins on the fixed part of the head. These are perpendicular to the light’s axis.
Let’s turn them, so they are longitual.
Then - the bottom of the fins is a solid tube. Let’s remove it. Now fins are able to support the head.
Instead of the solid tube that’s one piece with the rest of the head, take a separate one. And not solid - a mesh.
Wrap GoreTex or another fabric-attached membrane around the mesh and put below the fins.

So…it has quite large membrane are relatively to the head volume. Is that enough to enable easy zooming?
Also, I’m not happy about membrane exposition - it is quite easy to pierce it.
But maybe with some refinements it has a chance of working?

I have no grasp of how permeable that stuff is, but it appears, VERY:

https://www.gore.com/system/files/2018-11/GORE-Pressure-Vents-Datasheet-EN_0.pdf

I added 3 builds with precollimator lens. Including 2 zoomies which appear to have a hole in the middle of the flood beam.
Disappointing. :frowning:
I think that it can be avoided - after all camera lenses don’t have ringing issues like that. But how?….

The flood beam is also much narrower when you use a pre-collimator. Pre-Collimators only make sense when the focussed hotspot and/or the efficiency is of primary importance to you.

Thank you Argo for this post, I found some cool new designs I have never seen before!

When using a pre-collimators with a lens,
I have always wondered at what angle does the light just want to “bounce off” instead of go into the lens when the angle reaches high enough.

How much does AR coating help with this?
Is there a general guideline or table that can show the transmittance relative to the angle?

Reflections of light hitting lens at angle can be calculated from Fresnel equations
Yes, AR coating helps. But each AR coating is designed for some angle of incidence and works best there. If you read that UCL is 99% transmissive - that’s just with light hitting it straight ahead, at other angles of incidence the reflections will be stronger.
But at other angles AR coating helps too…and is actually quite critical when the angle is high.

I believe that aside from professional lenses pretty much all AR coatings are designed for light that hits them perpendicularly (which is not optimal).

Simulator - Ray Optics Simulation a free program to play with lens configurations, a unvaluable help to design a system with less invest in different samples. i am designing a searchlight with precollimator system and this program helpme a lot. The main features of optics was on my mind, but whit this program you can emulate fast the possible efects of the light without a continous ( and expensive) trial and error.

Any way i need to say later of saw several designs of precolimator proyects here, the first stage would be ever a half ball lens, not plano convex lens having a part only of the ratio curve. the better system to collimate is a complete sphere, but there exist the problem o poor light collection.

I feell a litlle half ball lens like collector and a medium size plano convex with AR coated should work like the combination.

My prototype have a medium size plano convex+ 1 fresnel of 100mm dia. and i am geting a nice 1.7 millions of candelas with only 10 watts in the new osram leds. And the spot size is very adecuate for a searchlight use. Now i am waiting the arrive of the half ball lens samples, to see if i can compact the design to have a size head more litlle. My concern is not loose more light in the edges of the primary collector, and a better beam angle to the secondary to not loose any light in the head walls.

A half ball lens should be the answer.

Interesting, thanks for posting. :slight_smile:

Yes, spherical lenses ("half ball") are suitable for use as pre-collimators.

I know this is a super old thread but the Nebo O2 Beam was of this design as well and is the first I ever saw which sparked my continued interest in designing a light this way, which is how I came across this thread.

1 Thank