Exteral Lenes

[stevetexas]

Here is a overview of the lensing - rightmost is furthest form the diode and the lens does convex side up, flat side down.

 

[stevetexas]

here's the spot at waist high (3.5 feet above the laser)

 

[stevetexas]

here't the spot at arms length - maybe 8-9 feet. For reference, that's part of my thumb in the photo...

 

[stevetexas]

this will light matches up to 6 inches, but I can't post the video - too much memory...  SenKat, can you help if I e-mail it to you?

 also, these new pictures I will be posting are with the new lens from Optics-online.com  that I mentioned earlier in the post - not scratched up like the lens from the red pointer that I used in the pictures thus far...

 Going outside to get some beamshots and piss off the neighbors...  

 

[stevetexas]

I have my camera in nightshot mode, but no "camera trickery" - I'm not that savvy...

Thye brighter of the two is always the >50 mW with the divergent beam and the other is a leadlight I modded to 30 mW for comparison... no fog, no smoke just green. In some pictures you'll see rooflines and a pine tree.

 

[stevetexas]

another shot

 

[stevetexas]

here's the 30 mW beam on a pine tree 300 yards away...

 

[stevetexas]

and the >50 mW on the same tree...

 

[stevetexas]

The real difference here is because of 2 things, one is the mW output, the other is the divergence. The 50 mW is now probably putting a 20 foot spot at 300 yards but has a pinpoint spot within 6 inches. That is why I can light matches AND have a very wide "starwars" like beam.

Most of these lenses are plano-convex (flat on one side and curved on the other...)

If you mod your pointer by turning the lens upside down - flat to the diode and curved to the aperature... You may have a similar result.

 

[SenKat]

You should try a plano concave for better divergence - exagerated - it would look like a cup - with the opening towards the guts of the laser, and the flat towards the point of emission.

 

[stevetexas]

here's a video it it burning matches - hope it works...

 

[stevetexas]

Sorry to Hijack the thread...

I just wanted to show you what I did with lenses internally that could also be used externally (since the thread is about external lenses). It is a pretty neat effect and really increases to burning power of the laser up close and looks like a focused flashlight beam at a distance.

Also, for my leadlights I've taken someone's idea to use a fliptop toothpaste lid as a dustcap and incorporated it as a lensholder/filter holder by placing the lens inside the cap and placing the cap over the end of the leadlight.

 

[timelord]

i'm sure like myself that your input into this thread is very eye opening. i certainly enjoyed reading your review as well as viewing your photos too.

 

[stevetexas]

The whole modification of this pointer started because I scratched the original lens - I was pissed and started throwing things together. Somehow I got lucky - it sure wan't skill or planning.

 

[SenKat]

The whole modification of this pointer started because I scratched the original lens - I was pissed and started throwing things together.  Somehow I got lucky - it sure wan't skill or planning.

I ran into the same issue with a 120mw fleabayser I have....I ended up using a lense from a dvd burner to get the better focus...looks DECENT but I really need the original lense in it for top power and looks.

 

[neocacher]

Has anyone used any of the old fashioned hard contact lenses on their laser. I think this would work and I dont think that they would melt if used on 100mw or less lasers?

Neo