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What type of artifact is this?

carulli2

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Good morning,

I had to modify the housing on a DTR G8 lens and I am worried that I have damaged it. The diode used is a 12X 405nm (can't remember specifically what one). Does anyone know what would cause this kind of artifact? The picture is of the dot at about 10m.20190325_091246.jpg20190325_094902.jpg20190325_094837.jpg
 
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GSS

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It would really help if you took a pic on a smooth white wall surface or any non patterned wall.
 

GSS

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Yikes! It looks like it's reflecting the inner barrel threading??
Did you take out the lens at any point? What kind of basic modding did you do?
 

carulli2

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Yikes! It looks like it's reflecting the inner barrel threading??
Did you take out the lens at any point? What kind of basic modding did you do?

I took out the lens, shortened the barrel, and then re installed the lens.

You can't see the circles if you are just pointing but if you turn the laser on and walk up to the dot on a distant object it looks like the photos. You can't see the circles if you are pointing at something close either.
 

GSS

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Are you sure the lens seated proper when you put it back in and there are no burrs after cutting the barrel?
 

carulli2

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Are you sure the lens seated proper when you put it back in and there are no burrs after cutting the barrel?
I seated it multiple times while trying to eliminate the artifacts. It never went away. There may be something that I missed though.

Edit, just did it again, no change.
 
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paul1598419

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Which side of the lens housing did you cut down? I think the lens housing is too long too, but I haven't tried it in another housing, which I have. These are longer FL lenses than the aspheres we use for greater power output, so they needn't be as long as they are, but I wouldn't cut the lens down. You can buy brass lens housings on eBay for these and other types of lenses. I believe mine cost ~$1.00 each.
 
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carulli2

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Which side of the lens housing did you cut down? I think the lens housing is too long too, but I haven't tried it in another housing, which I have. These are longer FL lenses than the aspheres we use for greater power output, so they needn't be as long as they are, but I wouldn't cut the lens down. You can buy brass lens housings on eBay for these and other types of lenses. I believe mine cost ~$1.00 each.
I cut down the side that the inner lens holder threads in. With this lens I think that is outward facing side, the side that the beam leaves from. I don't even see where the light could be hitting any threads...
 
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paul1598419

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Just a thought, but did you try turning the lens around in the housing? I'm thinking you might not have put he lens back in the same way it was in the housing before you cut it down.
 

carulli2

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Just a thought, but did you try turning the lens around in the housing? I'm thinking you might not have put he lens back in the same way it was in the housing before you cut it down.
I just tried it to be sure and I had it the correct way originally.
 

paul1598419

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Then, I would suggest you try a different housing at this point. It is really all you have left. That, or buy another G8 and don't cut that one down.
 

carulli2

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Then, I would suggest you try a different housing at this point. It is really all you have left. That, or buy another G8 and don't cut that one down.
Sadly I would need it cut down. I will try and find some short housings on ebay but I havn't had any luck so far.
 

RedCowboy

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If I want my adjuster to bottom out at say : ( a perfect infinity focus ) I simply push my module back into my host and tighten the set screw so that my adjuster bottoms out at the desired focus by adjusting the module depth, there is no need to cut down the lens barrel, I would rather add an additional set screw than contaminate a good lens, also you may have contaminated the lens surface/coating with natural finger oil or damaged the lens coating. It's best to avoid taking apart any laser lens as they work best when factory clean with their coatings intact. I always use compressed air or a hand puffer to blow away dust and avoid ever touching any laser lens.
 

carulli2

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If I want my adjuster to bottom out at say : ( a perfect infinity focus ) I simply push my module back into my host and tighten the set screw so that my adjuster bottoms out at the desired focus by adjusting the module depth, there is no need to cut down the lens barrel, I would rather add an additional set screw than contaminate a good lens, also you may have contaminated the lens surface/coating with natural finger oil or damaged the lens coating. It's best to avoid taking apart any laser lens as they work best when factory clean with their coatings intact. I always use compressed air or a hand puffer to blow away dust and avoid ever touching any laser lens.
Sadly this isn't an option for me.
 




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