Aspheric Lenses... What are they good for?

Just as the title states... what are aspheric lenses good for? I received mine in the mail today and immediately popped it in to my 3D Maglite Terralux 5 watt and the results are quite disappointing... I thought the beam would be brighter, sharper, throw further, etc, and I got none of those. I also put the lens on my 2D stock incandescent Maglite that i was planning to use for my ROP mod, and again worse. So what are its advantages? Because so far I do not see any.... maybe I am missing something? :shrug:

For maximum throw with an aspheric, it should be focused so you can see the shape of the die. However, some LEDs work better than others (smaller=better). If the LED is larger, it probably wont be as impressive.
The type and size of lens also matters.

I'd be willing to bet you forgot to remove the reflector...

That, or you lens is of the wrong focal length for a MagLite.

Marduke said:

I'd be willing to bet you forgot to remove the reflector...

That, or you lens is of the wrong focal length for a MagLite.

Click to expand...

I even tried that. With and without the reflector... sad thing is it looked like it was worse without the reflector...

CaNo said:

I even tried that. With and without the reflector... sad thing is it looked like it was worse without the reflector...

Click to expand...

I was referring to its throw. Compared to a tightly focused beam without the lens...

Flood is better i guess, but not great.

Aspherics are meant for throw. Yours is either assembled incorrectly, or is simply not the correct size for your Mag setup.

Flood shouldn't be better with an aspheric that is focused properly. The onyl spill you will get is the projection of the reflector. If you are getting a solid round circle of light, then it is not focused correctly.

Aspherics produce much smaller beam angles than reflectors, so the light can go farther without losing as much brightness.

Marduke said:

I'd be willing to bet you forgot to remove the reflector...

That, or you lens is of the wrong focal length for a MagLite.

Click to expand...

I think your right about the focal length... I ordered this one from DX after reading up on some of the threads about aspheric lenses. This was recommended...

I will try to find the link.

Did you try unscrewing it all the way, and even moving it with your hand away from the light until you see it completely focused?

divine said:

Did you try unscrewing it all the way, and even moving it with your hand away from the light until you see it completely focused?

Click to expand...

Yes I had gotten a tight square box in the shape of the led by doing this. Sadly it was only focused that way when the actual head was off and 2 inches away from the body...

I ended up getting the wrong one didnt I? Or is there a way to mod it to fit?

Can someone tell me the proper focal specs for the Maglite so I can find another one or throw a link my way perhaps?

That would depend somewhat upon your specific light source and setup.

But most importantly, you need a lens with a focal length in the range of the standoff between the LED and lens.

look at the deft threads. there are good pictures in here showing set up. Saabluster who makes them isa also now using a pre lens before it hits the aspheric. he also uses a diffused aspheric lens which looses the square chip shape at the expense of a little range.

it is interesting.

are there not dedicated mag drop in solutions like malkovs ? may be more cost effective unless its the fiddle factor that is attracting you?

Marduke said:

But most importantly, you need a lens with a focal length in the range of the standoff between the LED and lens.

Click to expand...

wouldnt that mean, if makes no difference at all, if reflector is mounted, or not?
It just forces all the "spill" light out, that would be wasted at the sidewalles instead
:thinking:


unscrew the head and try again with the aspheric.
Look if You get some spot beam and how the distance to the led is now (compared to the position when mounted in head)

looman said:

look at the deft threads. there are good pictures in here showing set up. Saabluster who makes them isa also now using a pre lens before it hits the aspheric. he also uses a diffused aspheric lens which looses the square chip shape at the expense of a little range.

it is interesting.

are there not dedicated mag drop in solutions like malkovs ? may be more cost effective unless its the fiddle factor that is attracting you?

Click to expand...

The Malkovs were a bit pricey and i ended up going with a Terralux drop in instead which is more than enough for me. I had ordered a lens from dx but from what was mentioned above, the focal is off, which is a shame because the fit is perfect for the Maglite. Oh well just because it fits doesnt mean it is right I guess. What other alternative Lenses do i have to choose from?

It is the fiddle factor, but fiddling is no fun when you get the wrong items to fiddle with lol :shakehead

I will look into this "deft" thread you speak of.

yellow said:

wouldnt that mean, if makes no difference at all, if reflector is mounted, or not?
It just forces all the "spill" light out, that would be wasted at the sidewalles instead
:thinking:


unscrew the head and try again with the aspheric.
Look if You get some spot beam and how the distance to the led is now (compared to the position when mounted in head)

Click to expand...

I get the tight beam i was looking for by doing this, but with the assistance of my hand being the bridge from the head and the body of the flashlight, which does not seem very beneficial in a real world situation, since my hand will often shift and make everything out of focus... :shakehead

Marduke said:

That would depend somewhat upon your specific light source and setup.

But most importantly, you need a lens with a focal length in the range of the standoff between the LED and lens.

Click to expand...

I am using a standard incandescent 3D maglite with a 5 watt Terralux drop in.

You won't get a satisfying aspheric beam with a LuxV.