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some clarification and questions regarding lens choices

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My needs are a bright solid beam with low divergence. I'm not terribly concerned with the beams diameter more that it keeps its shape as far out as possible. Dot shape and appearance isn't very important either and I am not that into burning stuff. I really am in it for the beam.

So this being said I have read and understand the basics of the 2 most common lens choices sold by DTR with whom I am going to order from. My confusion comes from reading conflicting opinions about the G2 vs. Three Element Glass lenses. Some say for my needs go with the 3 Element others say the divergence improvement isnt that drastic and isn't worth the loss of 30% power.
Could people give me their 2 cents as to what they feel would be best for my needs and why.

Also, if I just bought both types is it possible to interchange from one lens to the other easily or would the laser have to be taken apart?
Thanks
 

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You can just unscrew one lens and screw in the other anytime no problem. What you really want is a beam expander but I don't want to comment further because I haven't used one yet, anyway am not sure if there is one that fits our standard lenses/modules.

Alan
 

Alaskan

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Pi R S has a good point, just have both lenses, swap them out to your liking, easy.

I'm interested in lasers for the maximum delivery of light at a distance, I don't care to burn things or have a thin beam myself. I've looked for a way to make a simple beam expander which can be used with a G2 type of lens (but with a longer FL) and I think it can be done with a super long threaded lens holder of the same size by inserting a small expander lens in the tube first ahead of the collimation lens. After all, 532nm lasers no matter how small are already doing this to reduce their divergence.

Better yet, I believe a low loss expander can be made to reduce divergence by not putting a lens so close to the laser diode, as is done with a G2 lens, and letting its output expand a few inches before collimation, but I don't see anyone doing that with their pointer hosts yet. Doing so, you would have a much larger diameter collimation lens.

Here's a cheap 650nm laser which uses a large collimation lens placed much further ahead of the diode to produce a fat beam which as a result has a lower divergence:

http://www.ebay.com/itm/Fat-Beam-15...-for-Stage-Lighting-DJ-Show-Clu-/290876320972

Here's a inexpensive 50mw 532nm fat beam version of it:

http://www.ebay.com/itm/532nm-50mw-...e-Stage-Lighting-3VDC-Fan-Mount-/371217488307
 
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Shakenawake

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if you want to save some money, get these instead of DTR's g lenses. they are pretty much the same, I can't tell the difference between them and a g lens (in terms of power and beam quality)

http://www.aixiz.com/store/product_info.php/cPath/43/products_id/461

only bad thing was I got about ten of them, and every single one needed cleaning before use, kind of a PITA, but saves at least $22 per lens. this is about the same price as 3 element lenses

if the beam is what you want, i say get the 3 element for multi mode diodes, and the single element for single mode diodes.
 
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Thanks everyone. I got some great feedback. I think I will get the 3 element glass lens for now and order some of those G2 like lenses linked here later on when I have bought all my diodes. I'm a bit custom host heavy and a bit diode light ATM, lol!

Cheers,
Jeff
 




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