Aspheric on ROP?

[jake25]

I tried a search and nothing came up, it doesn't seem like people have discussed this. probably some simple reason why.

but has anyone tried an aspheric lens on a ROP? where would i find one?

 

[mr.squatch]

Light still comes out, but it's not pretty. The effect an aspheric lens has on the output light is that it mirror's what it looks like and sends that down the pipe. A horizontal coil filament never comes out pretty, I got a mag85 to look good but the lens was about 2" in front of the light end. My 66458 has a vertical coil so it puts out a nice round hotspot. Aspherics are generally used with led's since they make a neat square pattern beam, as the light source (emitter) is a square. I have a few lenses around on other lights, so I try it on every new bulb light I built, so far the 458 is the only one that spaced out correctly and looked halfway decent.

g

 

[2xTrinity]

Another, more significant reason why aspherics are ill-suited for incandescent filaments is that with an LED, most of the light is emitter forward, this is especially true in the case of a Cree XR-E, where most of the light can be captured by the lens. In the case of an incandescent, the light is isotropic (360-degree), so only a small angle of that would hit the lens.

There is a way to collimate all the light using an aspheric lens -- that is, use an elliptical reflector, which has two focal points -- position one at the filament, the other at the lens. This is how projectors works, but as far as I know, it would be nearly impossible to fit the appropriate reflectors/optics inside a maglite.

 

[Fulgeo]

I have been getting very good results with aspherical lenses on my 2xA123 5761 Mag61. JJ and NL have a good tread going here http://www.candlepowerforums.com/vb/showthread.php?t=179681 on the subject. So long as you go with a PCX or PMN lens with 250-300mm+ focal length you will be fine. Really seems to clean up the artifacts in the beam. On distant targets the Mag61 with an aspherical lens rocks. The good news is that SurplusShed sells alot of them for $4.00. The stock mag lens housing can utilize 50mm-52mm diameter lenses with no problem as long as the edge thickness is 4mm or less. We are still testing which lenses work best. The tread mentioned above has the actual lens that we have tested and have posted positive results. I think the reason why people do not think aspherical lenses will work with incandescents is because they have tested the issue with 34mm-37mm focal length lenses best suited for LED mods. Happy moding!