My Tiny Green Giant (505nm) Copper Build with Beam Shot

[Accutronitis]

I just read that the DTR's 520nm AR Coated Two Element Glass Lens is said to work very well at removing the "green beam box" and really cleans up the beam with the green laser diodes and doesn't rob as much power as the three element glass lenses, https://sites.google.com/site/dtrlpf/home/glass-lenses And it only costs $8.60 to boot ! :beer:

 

[paul1598419]

Who has made the claim that these 2 element lenses have no part of that rectangular artifact when used with these 503nm diodes? I don't want to order them unless I can be sure of this as a remedy.

 

[Accutronitis]

The OP did in his thread http://laserpointerforums.com/f45/1-3-1-4watt-520nm-ndg7475-green-bullet-build-98289.html

The green box was really bugging him and he said that lens worked for him......

 

[paul1598419]

That was with the multi mode 520nm NDG7475 diode. I would like to see something done with these 503nm single mode LDs. The artifact is there in the multi mode 520nm, but that doesn't guarantee that it will work with this diode. I have used multi element glass lenses trying to remove that artifact without success.... even with 500nm to 550nm AR coated lenses.

 

[Accutronitis]

I thought the multi mode diodes artifact was worse then the single mode ? But besides that i didn't guarantee that it would work with this diode, I just figured for only $8.60 it was worth a try if it could work as well as it seems to with the multi mode diodes ?

 

[dden4012]

Hey Paul the 2 element lens does help a lot when compared to the g2 lens. Its not perfect but much better than the g2. Similar to the 3 element but less side splash with the 2 element.

 

[paul1598419]

I get that. Nothing is worse for this artifact than the single element asperical glass lens. My point was that it is still there with all glass lenses. The only remedy I've found is an uncoated acrylic lens. I have yet to see any bit of it with these lenses and until I find another remedy, they are all that I am using.

 

[RB astro]

Paul I'll have to find one of those you're referring to and try it out.

I found another lens in my kit, I assume it's a three element see below, correct?
It did improve the artefact quite a bit compared to the G2 but it's still evident.

 

[paul1598419]

Yeah, Andrew. That's a multi element glass lens and it has the artifact. The uncoated acrylic lenses are very easy to find. They are the free lenses sent along with modules when you buy them in multiple quantities. They come with a black plastic lens housing that is very short. So much so, that the infinity focus is just a couple of turns away from being flush with the top of the module.

 

[RB astro]

Great thanks Paul, I'll see if I have one somewhere.

:thinking:

 

[paul1598419]

BTW, Andrew. I noticed that the glass lens in your photo in post #40 is backwards. The slotted end goes toward the focus ring. It's that way on all lenses. So, when you find an acrylic lens, make sure the slotted end is away from the diode.

 

[RB astro]

BTW, Andrew. I noticed that the glass lens in your photo in post #40 is backwards. The slotted end goes toward the focus ring. It's that way on all lenses. So, when you find an acrylic lens, make sure the slotted end is away from the diode.

Ahh, thank you so much Paul.

:beer:

Edit: I just checked and the deeper slotted end is in the focus ring.
It's the one with the slot all the way from edge to edge that's in the focus ring.

Edit: yep I can confirm it's correct way because I turned it the other way and it's just a huge circle that won't focus at all.

 

[paul1598419]

Oh, then that one has that attachment to take it apart. I don't see those that often.

 

[RB astro]

Oh, then that one has that attachment to take it apart. I don't see those that often.

Rick Trent sent it as an extra with one of his builds.
He always send me two lenses, one for burning and the other for better beam spot.

 

[Mosc007]

The 2 Element does help a lot with Green beams. But it's still not perfect. There is some spatial light emmited at a wide angle from the beam. Not much power though.

I have tested it with 520nm and 505nm. Same results. Much better than G2 but still some reflections.

 

[paul1598419]

That has been my experience as well. Only the acrylic lenses that have no AR coating give a clean dot. I don't know why this is the case, just that it is.