Questions regarding Aspheric lenses

[Guy's Dropper]

I have a couple of questions regarding aspheric lenses:
1. Where can I buy a glass aspheric lense that would fit a D size Maglite?
2. Do aspheric lenses only work for led lights or do they also work for incandescent lights?
3. Do aspheric lenses project into the head of the light in any way, possibly inhibiting the space required for a larger bulb?

 

[Norm]

http://kaidomain.com/ProductDetails.aspx?ProductId=1753
Norm

 

[Guy's Dropper]

So, can that be used with an incandescent. If not, why?

 

[Norm]

You end up with a projected image of the filament, in other words a nice bright curly wire, LED just projects the image of the LED die.
Q3. No.

 

[Guy's Dropper]

Darn! Aw well, thanks for the help.

 

[Data]

So, can that be used with an incandescent. If not, why?

As Norm says you get a nice projection of the filament if you place it right at the focal point. If you don't you will get a smoothed but larger spot.

An emitter like the Cree directs most of its light in a 90 degree cone. If you get an aspheric lens with a short focal length relative to its diameter it can capture a good portion of that light from the Cree. An incan bulb throws its light in every direction. Less than 1/6 of its light will go to the aspheric lens.


Cheers
Dave

 

[Guy's Dropper]

What if I had a reflector as well as the aspheric lens on an incandescent flashlight.

 

[Data]

Sorry Guy's, that will not help. Only rays emanating from the focal point will be projected in the desired direction.

 

[Guy's Dropper]

Ok, thanks for responding.

 

[Teego]

I've been doing a bit of experimentation using diffusing filters to homogenize the light source and reduce the led die hotspot in an aspheric setup.

This image from Edmund optics got me headed down this path. I posted a question regarding holographic diffusers last week, but it ended up with no bites so I presume it's either something that will prove impractical in the end or it's just something that nobody has really messed around with much yet.

In as much as this might apply to incandescent setups, I only know how basic projector design works.

Now, ALL CAVEATS: I have no idea how the reflector/bulb/lens system performs in reality. Dave notes that less than a sixth of the light will make it to the lens in the first place without a reflector, and you would need a rather unique reflector system in place to make the focal length of the reflector match the focal length of the lens.

MAYHEM!

Using LEDs has been much more straightforward for me, though I have yet to figure out just how many lumens I am missing out on due to not having things optimally configured.

I hope I'm not spewing lies at this point. I'm a tinkerer at the moment, using my computer science background to pretend I'm an engineer. At any rate, good luck with things. Let us know if you continue down the incan + aspheric path. Could be some neat experiments if nothing else.

 

[waddup]

makes sense to me that any light emitted from either the led or bulb that doesnt exit the rear of the light should exit the front

correct reflector/lens combo should project 100% light forward AND in the beam pattern desired.

but ill wait for someone clever to design and build it then ill buy it,

after ive seen beamshots.