Laser lense?

[deltawars]

I'm new to laser's and i bought a host(from ebay) with a 3 elements glass Lens but it only has a focus point of like 5cm with a circle dot, and if i screw the lense in more it's focus point get's further away(not much only like 3cm) but it spreads out like a line effect And another thing i noticed was the beam crosses like the picture i drew below (why does that happen)?

So my question is what type of lense would i need to focus like this.

Also can people tell me about all the different types of lense, i have seen people on the forms say like G-1,G-2,G-3 what is the difference?

 

[Deleted member 17304]

Didn't you already post a thread asking this?

Try screwing the lens in farther. There's a focal point where it hits what you want it to be. no single lens will collimate a laser beam from any distance.

 

[deltawars]

yes i did but i also wanted to know what different types of lense are there.
And what i mean is just look at the lasers in your avatar picture the laser beams don't spread out after 5cm.

 

[Speedy78]

Because they are focused? The lens moves in and out. Screw it in all the way, screw it out all the way, the focus will change. At some point in there you will be focused to infinity.

I see you mentioned a line. Does it have a line lens on it? If so it will never apear to be focused to infinity. Just remove the plastic line lens. It will look like this if it does :