So I have been doing some experimenting with aspheric lenses and have decided to build a run at a mega Kcd thrower in the machine shop. With aspheric lenses of different diameters, a DEFT Enthusiast I own to study, and my aspheric lenses having differing focal points, the only real conclusion at the end of the day was which LED actually makes a better candidate. That's not even news, I don't believe. Heat sinking aside, of course the Cree XP-G2 92cri bins seem to be the emitter of choice for a lightsaber handheld aspheric. Whatever host it need be (2x26650/3x18650 hopefully, or minimal 2x18650 host), I will mate it to the components. I am thermally potting the driver, and turning a solid step-down-cylinder shape copper post to center the emitter die on near the focal point. I will remove the Cree LED protective lens, also.
My subject here is more shifted towards what the aspheric lenses are doing. Also, what lenses on LED lights are capable of doing for the focus of the LED projection in aspheric lights, but I use lasers here at times only as a basis for comparison in their optical properties, which are shared mostly by all lights.
In an optic system, we can compare what I see as being similar to what one might desire in an aspheric flashlight. A laser. A laser that emits light from a 0.01x0.01mm laser chip inside the diode. A single, 5mm aspheric lens is used to collimate its laser light into a focused laser beam, just like a focused die on the wall in an aspheric light is seen to be clear when in focus. The beam is small in the laser because the emitting surface is also small. Yet, the laser still has a divergence in the beam; it spreads out over distance. So, what is done is a "beam expander" is used. In this add-on beam expander, two lenses cause the exit laser beam to be much larger in diameter at the light exit, but it's divergence is then extended by the power of the lens, I.E., 10x for a 10x tighter beam. In other words, the light density is less when up-close while using the expander lenses, but the light density eventually becomes greater than the original light at a far distance and the "dot" can be seen on objects at a further distance. It's like shining a laser right through the back of a spotting scope!
The principle is the same with an LED, is it not? Say the light is focused, expanded/corrected, then refocused again to make its projection reach a farther distance? The difference between the obvious two is that the laser emitter is only a slice of the scale of the emitting surface of an XP-G2.
So, with all that said, is there a clear-cut reason this same type of beam expansion is not seen on the current mega-throwing flashlights like the DEFT-enthusiast or even DEFT-X? Why not take the output of an aspheric light, expand it to 3x, and obtain a light with 3x less beam divergence? Or, why use only 1 lens, in other words? I felt maybe, just maybe, there is some unforseen way using the right set of optics, that could make Kcd go through the roof like the laser princible. Apparently, I am not understanding the full physics, maybe the lenses' positions would need to create a light the size of a telescope...
More ideas here for a super thrower.
When is big too big, for an aspheric lens? Can it ever be too big? Say instead of a 35mm aspheric and an XP-G2, one used an XML2 and a 75mm aspheric. I would expect the total output area to be large from the XML2 of course, but would the light be any less dense over its covered area than the G2? Even similar? Of course, the LEDs being driven at their higher ends of amperage capability.
My subject here is more shifted towards what the aspheric lenses are doing. Also, what lenses on LED lights are capable of doing for the focus of the LED projection in aspheric lights, but I use lasers here at times only as a basis for comparison in their optical properties, which are shared mostly by all lights.
In an optic system, we can compare what I see as being similar to what one might desire in an aspheric flashlight. A laser. A laser that emits light from a 0.01x0.01mm laser chip inside the diode. A single, 5mm aspheric lens is used to collimate its laser light into a focused laser beam, just like a focused die on the wall in an aspheric light is seen to be clear when in focus. The beam is small in the laser because the emitting surface is also small. Yet, the laser still has a divergence in the beam; it spreads out over distance. So, what is done is a "beam expander" is used. In this add-on beam expander, two lenses cause the exit laser beam to be much larger in diameter at the light exit, but it's divergence is then extended by the power of the lens, I.E., 10x for a 10x tighter beam. In other words, the light density is less when up-close while using the expander lenses, but the light density eventually becomes greater than the original light at a far distance and the "dot" can be seen on objects at a further distance. It's like shining a laser right through the back of a spotting scope!
The principle is the same with an LED, is it not? Say the light is focused, expanded/corrected, then refocused again to make its projection reach a farther distance? The difference between the obvious two is that the laser emitter is only a slice of the scale of the emitting surface of an XP-G2.
So, with all that said, is there a clear-cut reason this same type of beam expansion is not seen on the current mega-throwing flashlights like the DEFT-enthusiast or even DEFT-X? Why not take the output of an aspheric light, expand it to 3x, and obtain a light with 3x less beam divergence? Or, why use only 1 lens, in other words? I felt maybe, just maybe, there is some unforseen way using the right set of optics, that could make Kcd go through the roof like the laser princible. Apparently, I am not understanding the full physics, maybe the lenses' positions would need to create a light the size of a telescope...
More ideas here for a super thrower.
When is big too big, for an aspheric lens? Can it ever be too big? Say instead of a 35mm aspheric and an XP-G2, one used an XML2 and a 75mm aspheric. I would expect the total output area to be large from the XML2 of course, but would the light be any less dense over its covered area than the G2? Even similar? Of course, the LEDs being driven at their higher ends of amperage capability.
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