The lens is probably out of focus and doesn’t project the image of the phosphor die.
EDIT : “High luminance at the laser light source provides valuable optical system advantages including narrow beam angle, sharp beam cut-off and smaller optical systems. Enabling beam angles smaller than 8 to 10 degrees from 25 to 50 mm optic diameter has been challenging with conventional light sources.
Utilizing laser light sources, beam angles of 2 degrees or lower have been demonstrated with total internal reflection optics of less than 30 mm in diameter, well within convenient lighting system form factor.”
” Source“:https://soraalaser.com/wp-content/uploads/2017/09/LED-Professional-Article-Issue-63-2017.pdf.
From the same source : “In each of the two configurations, up to 500 lumens is emitted from a light emitting area only 300 microns in diameter resulting in luminance levels in excess of 1 billion cd/m²”.
The absorption block is not at the light emitting surface, it is at the lens, which is significantly farther in front.
As the light rays spread out from the lens they cover up any hole that was created by the block.
You can only see the hole in the middle if the light is pointed up close, like a meter or less away.
If you eliminate the green triangle by blocking the center, the rest of the light will fill up the center hole after enough distance.
Yes and yes.
You would still need the blocking device attached to the regular lens on a reflector flashlight.
Also I’m not sure about how well it would perform with a reflector, the polar distribution may or may not be the same as a domeless LED.
There is no published data on the polar intensity distribution yet.
It’s actually not as hard as it seems if you have a high contrast, because ambient light causes the collar to project an inverted image.
For example, a tiny black dot on a piece of paper.
The collar will project a shadow identical to the dot.
You know it is in perfect z-height focus when the shadow is as sharp as the original dot, and you know it’s in the right x/y position when the shadow is on top of the original dot.
I see a lot of doubts about aspherics giving good throw, too be fare this and the weltool Lep fire the laser into the phosphor and intoa reflector that then sends it through the aspheric.
For a long long time I’ve been asking for a double aspheric lens flashlight to do what this is doing, a ridiculously tight beam in a narrow package. This does it even smaller.
Double aspheric lens had been the king of throw with led’s from 8 or 9 years ago. The setup was the a little bigger than an arm. It was a pencil beam with no spill.
I believe illum (illumination supply) had a code Spooky for Halloween for a discount.
It’s not a double aspheric. It’s a laser that points backwards onto a phosphor plate. That phosphor emits light which goes out the single aspheric lens.
The tight beam comes from the very high intensity allowed by the LEP, which is about twice that of the most intense available LEDs.
There is no “reflector” in the weltool.
Unless you’re talking about the 45 degree mirror in the center of the lens which has literally nothing to do with the beam or throw.
Is a double aspheric a flashlight that first uses an internal lens to produce a virtual reduced image of the light source inside the flashlight head which is then projected into the world by a second front lens? I have never seen such a flashlight but it will take up quite some extra length (like several cm).
To date I’ve never scene one factory made, just hobbiest made.
Their was a tutorial someone did on YouTube called LightCannon. Had 5 or 6 parts to the video. But that wasn’t the first one ever made. That one looks like it’s almost 3 feet long.
The length between lenses probably varies based on the led
I believe it can if it is a two-stage system with an intermediate image. The first (very short focus) lens creates a reduced size intermediate image that is projected by the front lens of the light.
Edit: on second thoughts it will not work because the reduction step by the first lens requires a limited incoming beam angle, so the secondary virtual light source (the intermediate image) will be reduced in size but the luminance will be the same. netto result: lots of light wasted and a smaller hotspot but without throw increase.
