500mw green laser focus adjust help

[Rulis88]

I've got 500mw 532nm laser pointer and I want to make this laser focus adjustable or at least find some ways to make it burn stuff more efficiently. Is there any specific lens I should buy? If so, which one? Any useful information will be appreciated.
>inb4 I should use magnifying glass. Magnifying glass doesn't work the same with lasers, idiot.

 

[justinjja]

What exactly is wrong with a magnifying glass?

I have a week green laser that can not light matches on its own,
But with a magnifying glass it can...

 

[Rulis88]

magnifying glass doesn't seem to take any effect on lasers.

 

[justinjja]

What laser do you have?
and what are you trying to burn?

 

[Rulis88]

Already told you, just a regular 500mw laser pointer and I'd like to burn basically any plastic.

 

[justinjja]

Well if your having trouble burning plastic, your "500mW laser" probably isnt 500mW.
That is why I asked what laser you have.

Try a magnifying glass with a higher X rating

after the magnifying glass you beam will have a slight hourglass shape,
You have to burn things where the beam is thinest

 

[Apocalypse]

>inb4 I should use magnifying glass. Magnifying glass doesn't work the same with lasers, idiot.

Uh... what? I'm pretty sure magnifying glasses treat all light the same as long as the wavelength of light can interact with the materials of the magnifying glasses.(Not passing through the glass (gamma rays) or being blocked by the glass (IR))

A 500mW laser should be able to burn stuff without magnifying glasses unless the beam is VERY wide...