How to achieve a certain beam pattern.

Flashlight Modding and DIY Parts
1

Hello All,

I am not sure anyone will be able to help me out on answering this question but… I am trying to figure out what optics, lens, what ever to get a very wide beam pattern from a LED. I am looking for a wide beam with very little spill on the top and bottom. Kinda like this == instead of oo00oo if that makes any sense?

Any help or pointers would be greatly appreciated!

2

So wide and narrow with no spill top and bottom? I want to clarify for others to help

3

There was a flashlight like this that existed a few years ago, it was called the rev captor that made a large horizontal spread of light without wasting it vertically.

http://www.candlepowerforums.com/vb/showthread.php?388745-Saabluster-REV-Captor-(3xXM-L2-3x18650-Flood)-Review-RUNTIMES-BEAMSHOTS-VIDEO

All you need is a cylindrical lens, and that will "flatten" your light in one axis but not the other.

You can also use something called a directional diffuser:

4

Yes exactly what I ment!

Could someone tell me where to get such a lens, by cylindrical you mean one that looks like round rod?

5

It looks like part of a rod:

Also I edited my first post, there’s an easier way using diffuser film if you don’t need a very sharp cut on top and bottom.

6

A spreader lens should do the trick alsoLens

For example

7

No, no, you just need a fresnel or wide angle lens.

https://m.ru.aliexpress.com/item/1299989764.html

People use these on bicycles all the time. Lots of places sell them.

8

This is literally just a bunch of cylindrical lenses put together.

9

Yes it is. Some people call them fluted lenses and the bumps flutes. Common on car headlights from the past.

10

Thanks for all the help everyone! I ended up ordering some glass cylindrical lens, I will have fun playing around with them.

11

Enjoy your tinkerin’ but you’re not making car head / fog lights are you?

12

I don’t know how far along you are with planning and gathering parts/materials for the build. Do you have a specific LED you want to use? If not, let me recommend the Osram KW CSLPM1.TG, otherwise known as the 2mm² “White Flat”. It is slightly rectangular already, and quite throwy when used in the right configuration. If you put it behind your cylindrical lens in the same orientation as the lens, it will amplify the “spread” factor a bit compared to using a “normal” square die or a round die emitter.

So, if your emitter is like this………

and the lens normally does this….

then you will effectively get this….[]

You can read about the “White Flat” emitters HERE if you haven’t already done so. :smiley: