CLOSED: G2 Lens CLONE Group Buy

[94Z28]

Closing the GB the order is placed.

 

[Sta]

Re: G2 Lens Deal Group Buy Interest

I like this. I'm in for 2 or 3 of them.

 

[Alaskan]

Re: G2 Lens Deal Group Buy Interest

I could use some, but I don't understand how one G2 has so much more loss than the other, what was the input power which produced the 200mw difference between two of them? Were they really G2, or something you are calling a G2, perhaps a G2 knock off?

 

[94Z28]

Re: G2 Lens Deal Group Buy Interest

I could use some, but I don't understand how one G2 has so much more loss than the other, what was the input power which produced the 200mw difference between two of them? Were they really G2, or something you are calling a G2, perhaps a G2 knock off?

What I'm being told is real G2 lens I will see if he has a spec sheet at all.

I was using one of my C6 with 1.8A driver on a M140. It registered 2200mw on another G2 (I think it's a DTR G2) and 1500mw on acrylic... then this new one showed 2400mw on the G2 from anomaly. I haven't LPM on these 3 elements I got in yet, nor have I got sanwu g7+G2 in yet.. will test more later. He actually told me later that is the regular occurrence with these lenses reading higher on power meters on average at least 8% higher.

I'm not saying 100% they're better or worse than all other G2 but they work well, has the same shadow as the other G2 but for only 10$ it seems like a deal to me.

I am still waiting to hear about the AR coating.. maybe that is the difference?

 

[Alaskan]

Re: G2 Lens Deal Group Buy Interest

I wonder what AR coating they have, I don't know enough about G2, or the G2 variants out there, whether they can be purchased with BBAR coating, or specific coatings to red, green or blue.

 

[94Z28]

Re: G2 Lens Deal Group Buy Interest

I wonder what AR coating they have, I don't know enough about G2, or the G2 variants out there, whether they can be purchased with BBAR coating, or specific coatings to red, green or blue.

I am not sure, but I know jayrob had versions of G1 with coatings for blue vs red.. at least that's what I got from reading through some of his threads?

I'm not real knowledgeable about optics at all yet, just being honest.. but I can read a power difference and the $$ difference also lol!

Let me know if your in and for how many Alaskan, aND any other info I can get will get added to OP.

 

[RedCowboy]

Re: G2 Lens Deal Group Buy Interest

What is the focal length compared to our standard G2 and a sanwu G2?

 

[Alaskan]

Re: G2 Lens Deal Group Buy Interest

FL can't be more than 8mm or the beam will get truncated with some diodes, good question, we can compare that with the specified FL for the G2. I bought a large number of "S1" lenses on a GB over a year ago for 3+ dollars each, but they weren't what I had hoped, the lens holder had a retaining ring which I thought was a bit too thick and the lens produced splash with my diode I didn't like, a normal G2 never did that.

 

[94Z28]

Re: G2 Lens Deal Group Buy Interest

What is the focal length compared to our standard G2 and a sanwu G2?

Unsure waiting to see if he can get me specs.. im not sure how to measure it..

 

[RedCowboy]

Re: G2 Lens Deal Group Buy Interest

The rear FL of a DTR G2 is 2.39mm I think or very close to it and the FL of a G7 is around 7mm, the 3 element is 5.3mm.

The sanwu G2 is different that the DTR G2 and is useful to me for my optical train correction of our most powerful common diode at this moment the 44.

I don't know the FL of sanwu's G2 but I think it's shorter than 2.39mm, I am not sure but I need to learn more about lenses as the curvature of the input and output play a role as well, aspheric biconvex is what they are and there is much that I don't understand, but it matters for our use.

https://en.wikipedia.org/wiki/Aspheric_lens

These look interesting but are probably just copies of our regular G2.

http://www.ebay.com/itm/405-G-2-Gla...063848?hash=item235da6bd28:g:O1EAAOSwf-VWVYBk

 

[94Z28]

Re: G2 Lens Deal Group Buy Interest

Shouldn't have opened my big mouth about power numbers as i just realized I sold my compared G2 LAST NIGHT smh. I sold the laser I tested this on originally as well.

Anyway, I did compare to the 3 element I have and the Anomaly G2 and will also re-run the numbers up once the Sanwu arrives. I did them back to back with my hyperion LPM.. what is this showing --- 9.5% increase?

I gotta figure out a stand for this maglite to run my LPM tests in it, because as you can see in the graph im holding it on the 2x2mm square sensor on the LPM....

3 Element

G2 (GB Ones)

 

[RedCowboy]

Re: G2 Lens Deal Group Buy Interest

The DTR G2 can give you a 30% increase in output over the 3 element.

 

[DTR]

Re: G2 Lens Deal Group Buy Interest

I could use some, but I don't understand how one G2 has so much more loss than the other, what was the input power which produced the 200mw difference between two of them? Were they really G2, or something you are calling a G2, perhaps a G2 knock off?

The only real 405-G-2 lenses come from Will @ laser66. Everything else is just using his name to get sales. His bare lens element even in bulk are still $20. The rest are just China G-2's that took the name as the 405-G-2 had great name recognition instead of making their own name for their product. With that said some come close to or as good as for pass than the original but most tend to have very slight beam differences. Lenses also seem to lose efficiency over time either from environmental contaminants even though you can't see them or damage to the AR coatings probably more pronounced when used with some of the higher power diodes. If you are not comparing a brand new lens to another brand new lens the older one usually will have less pass.

This came up a bunch in the G-2 vs G-9 where both lenses are near identical for pass with small variations from lens to lens but for the most part about 94-96% pass with 445nm light. Several testers got new G-9's and compared them with their old G-2's and vice versa and not to much to surprise they get higher readings out of the newer lens. Anyway they all being around 94%+ pass there really is not a whole lot higher you can go.

 

[94Z28]

Re: G2 Lens Deal Group Buy Interest

The only real 405-G-2 lenses come from Will @ laser66. Everything else is just using his name to get sales. His bare lens element even in bulk are still $20. The rest are just China G-2's that took the name as the 405-G-2 had great name recognition instead of making their own name for their product. With that said some come close to or as good as for pass than the original but most tend to have very slight beam differences. Lenses also seem to lose efficiency over time either from environmental contaminants even though you can't see them or damage to the AR coatings probably more pronounced when used with some of the higher power diodes. If you are not comparing a brand new lens to another brand new lens the older one usually will have less pass.

This came up a bunch in the G-2 vs G-9 where both lenses are near identical for pass with small variations from lens to lens but for the most part about 94-96% pass with 445nm light. Several testers got new G-9's and compared them with their old G-2's and vice versa and not to much to surprise they get higher readings out of the newer lens. Anyway they all being around 94%+ pass there really is not a whole lot higher you can go.

Thanks for clearing that up DTR and I know that Laser66 is the original G2 supplier I have a email out to them to purchase one lens..

I am pretty sure he wouldn't be getting them from that guy, and I am also certain they're not "real g2" because he is referring to it as a new version of G2.

Nonetheless if the coating holds up and they work for high power 10 bucks still works for one GB IMO.

 

[steve001]

Re: G2 Lens Deal Group Buy Interest

I could use some, but I don't understand how one G2 has so much more loss than the other, what was the input power which produced the 200mw difference between two of them? Were they really G2, or something you are calling a G2, perhaps a G2 knock off?

Two reasons why come mind.
The AR coating and the type of glass. Edmund Optics shows graphs how different types of glasses perform vs wavelength.

And I think "numerical aperture"

Another reason? Understanding Optical Specifications

Manufacturing Specifications | Surface Specifications | Material Specifications
http://www.edmundoptics.com/resources/application-notes/optics/understanding-optical-specifications/

 

[94Z28]

Re: G2 Lens Deal Group Buy Interest

Bump. If I cant get any more interested people guess me and Sta will have to be the group LOL.