OMG How to make a dangerous laser even MORE dangerous !

[Accutronitis]

I had some old camera lenses collecting dust so I decided to tear them down for the lenses and I ended up of course with a bunch of lenses BUT I ended up with two small lens assemblies.......



The larger of the two looked interesting.....



So I thought lets try holding it in front of the 44 Hammer like so and see what happens.....



With it shooting across the room it seemed to be expanding the beam BUT I noticed at about 3 inchs away from the lens the beam was very noticeable converging to a extremely small point so I put that point on a piece of wood and OMG spark like ambers started shooting out from the wood along with flames and you could hear it as well !!!

It was a little scary because even with my laser safety glasses on the focal point was very bright like a arc weld and I only did it for a few seconds but I saw spots for a couple of minutes after words ! I think to do that again i'll need to use a pair of welding glasses !!!

 

[RedCowboy]

I'm telling you man, get a beam expander mounted on the end and you will love it, that fire you hear pop on your desktop will be zoomable across the room, it's a lot of fun but safety 1st as always.

Here's an old video of a 44 with a G2 and 6X pair finished off with a 3X BE, at 14 feet a popsicle stick thicker than a penny pops out a flame kernel.
The unit is my moped muffler, it was a test bed to see if I could adjust the G2 on the fly and was going to have a flat top with a thumb wheel but thread slack was an issue, fixable but not worth it so it became a proof of concept for the BE after correction.

I have bought several metric taps for the 3X, just got an M11 x 0.5 and it is not metric so I am going to improvise on that last corrected build I posted in your thread, I really want to combine 2 x 44's or knife edge 4 x 44's and they will all be 6X corrected then fed into a BE.

This is close to what I am looking for but it says 4mm is the input beam limit, 4 knife edged 6X corrected 44's beams each about 7mm wide will need a BE about twice this size but it should get 7-8X, actually I want a fixed 7X or 8X ratio and no relay lens, just about a 90mm objective lens and that will be a pyro delight......safety 1st as always.

ThorLabs BE02-05-A - Optical Beam Expander, 2X-5X Zoom, AR Coated: 400-650 nm | eBay

 

[Accutronitis]

I'm telling you man, get a beam expander mounted on the end and you will love it, that fire you hear pop on your desktop will be zoomable across the room, it's a lot of fun but safety 1st as always.

Here's an old video of a 44 with a G2 and 6X pair finished off with a 3X BE, at 14 feet a popsicle stick thicker than a penny pops out a flame kernel.
The unit is my moped muffler, it was a test bed to see if I could adjust the G2 on the fly and was going to have a flat top with a thumb wheel but thread slack was an issue, fixable but not worth it so it became a proof of concept for the BE after correction.

I have bought several metric taps for the 3X, just got an M11 x 0.5 and it is not metric so I am going to improvise on that last corrected build I posted in your thread, I really want to combine 2 x 44's or knife edge 4 x 44's and they will all be 6X corrected then fed into a BE.

This is close to what I am looking for but it says 4mm is the input beam limit, 4 knife edged 6X corrected 44's beams each about 7mm wide will need a BE about twice this size but it should get 7-8X, actually I want a fixed 7X or 8X ratio and no relay lens, just about a 90mm objective lens and that will be a pyro delight......safety 1st as always.

ThorLabs BE02-05-A - Optical Beam Expander, 2X-5X Zoom, AR Coated: 400-650 nm | eBay

My 12X Cyl setup does that right now if I adjust the last lens to that focal length.

One thing is with the Milos 12X setup the exit beam is about 10mm x 4mm so I don't see it making it into a BE unclipped ?

How big is the input lens on the 3X BE and can you show me a picture of it ?

 

[RedCowboy]

Sure if you want to keep adjusting your set up, but if you dial it in for middle of the road you can let the BE adjust you across the range, unless you can arrange a super fine thread adjuster for your lens but you also gain with the BE, imagine setting up for your favorite distance then cranking in 8X on top of that, at some point you need more power but getting a what you have all into a small area is the next best thing.

But I digress.

The opening is 8mm in the clear, I have pics but can't find them so here's a quick shot of the opening, the exit or objective is 35mm in the clear.

 

[Accutronitis]

Hum, I need to work on getting my exit to 8mm or under, I Wish milos was still around because I have some questions for him.....

Sure if you want to keep adjusting your set up, but if you dial it in for middle of the road you can let the BE adjust you across the range, unless you can arrange a super fine thread adjuster for your lens but you also gain with the BE, imagine setting up for your favorite distance then cranking in 8X on top of that, at some point you need more power but getting a what you have all into a small area is the next best thing.

But I digress.

The opening is 8mm in the clear, I have pics but can't find them so here's a quick shot of the opening, the exit or objective is 35mm in the clear.