Secondary optic? How does that work?

[netprince]

I'm getting ready to assemble 4 MC-E modded mags with aspheric lenses for some friends of mine. I noticed that the DEFT uses a secondary optic for increased output, as well as a few other lights. The secondary optic appears to be an additional lens located very close to the emitter.

Can someone help me understand what kind of lens this is? Does using a secondary optic require a different aspheric lens? What are the tricks to selecting the correct secondary optic to match with your primary?

Thanks!

 

[mash.m]

hi,

that is an interessting question!

i think that the optic at the emitter must bundle the light and the second (asherical) must focus the image.

i have also done some tests with two ashperical lenses but the result was not good at all.

markus

 

[Nos]

i have done a lot of testing yesterday with more than 20 lenses.

i dont have a luxmeter here, so i cant tell you what is "the best" setup but i can tell you how to get the maximum light out og the front.
basicly you need 2 lenses....you could use even more, but its difficult to align those and every lens absorbs light, so you have to use high quality lenses.

here is what i found out and how the setup works (best)

the secondary optic at the emitter precolimates the light for the bigger primary lens.
when you but the sec optic in front of the led you will that notice the emitting angle of the led becomes smaller for a XR-E from 90° to ~70.

when you now hold the pri lens over the other lens you can clearly see the edges from shadow to light .....this edge shows you that the sec lens catched all the light from the led and this light is now focused by the pri optic.

note that the precolimating from the sec lens allows the pri lens to be used at a shorter focal lenght.


i hope could help you at least a bit...... its quite hard to explain

 

[netprince]

NOS: Very interesting. I would like to try some lenses. What type of lens would you recommend, and where did you get yours?

 

[Nos]

one of the best sec lenses i have found is this one

http://www.kaidomain.com/ProductDetails.aspx?ProductId=1850


It has the highest light transmission and surpasses even some from the surplusshed high quality ar coated lenses. its the best of ANY KD and DX lenses from 16-44 diameter ( i tried them all :green: )

the pri lens i am going to use is from MC lag-123 for a mag 1D


In another build i am going to use a 110mm projector lens...........the bigger the pri lens the further it will throw, and most important.....it is able to catch all the procolimated light from the SKU 5162.......
This setup with a XR-E Q5 @1A is too bright to look on at the ceiling.........brighter than my N30....a lot more brighter
.i dont know the lux, but in theory this build has the potential to be brighter than the Deft (when running with a R2@1,4A )

 

[netprince]

I'm guessing your install it with the curved side away from the emitter? I'm going to have to order a few of those for testing. I wonder also what you used to suspend the secondary optic?

Your light sounds really bright. Would like to see pictures of the optics...

 

[Nos]

pictures -.- ermmmm if i had a hand free, right away

i really have to make/find some optic holders ( i wish i could turn them myself -.-) and a plastik tube host
.........

all lenses have their flat side to the emitter.......

all i can say is get the biggest lens you can fit in your host as pri lens, and try the one i suggested or any other "short focal lenght" lens as sec optic
(i bought/collected ~30 lenses to find that out and proof it)

it really is a bit about trying

 

[Nos]

this is how it works. nothing new here, light the normally would miss the pri lens is now beening directed into it. ( the sec lens is much to big in this example, but the focal lenght might be right )

 

[Nos]

and here is some kind of codenser optic

wide focus

tight focus

i guess this is how the X6 Ostar works, you just need to move the 3rd lens a little bit to focus the beam........but thats just a model, i spend hours alinging lenses to achieve this.........and i wont even fit in a host

 

[netprince]

Wow, great models! I am going to have to find some other optics to try some of this.

 

[bshanahan14rulz]

Is there a free alternative to whatever program you used to create those models, NoS? That sure would be useful, I've been wanting to see effects of multiple lenses for a while, but don't remember how to draw asperics by hand

 

[Th232]

Is there a free alternative to whatever program you used to create those models, NoS? That sure would be useful, I've been wanting to see effects of multiple lenses for a while, but don't remember how to draw asperics by hand

+1, I'd also be interested if there's such a program around.

Don't have the cash to buy a whole stack of lenses and have them sent to Australia, especially when I know most of them will never be used again.

 

[Paul Baldwin]

That looks very similiar to something I found here?
http://webphysics.davidson.edu/applets/Optics/intro.html

Paul.

 

[Nos]

its the same, but i found it on a different website

but this is just a simple programm.....you can draw some models and thats it.
a professional calculating or simulationprogram would be nice indeed