New G7 lens for 445nm / 462nm / 520nm

[RedCowboy]

The edge clipping is just on the highly divergent axis and is about 20% , some say you gain 30% the other way, but at a cost of 400% the spot size if switching to a G9 G2 G1

I could make a video but I will explain what happens with the 3 element issue.

With a new 3 element at 14 feet I get a tight focus with a 7875 and a line burns in plywood in about 2 seconds, in pine it takes about 1 second.

Now if I put in a well used lens that is clean, you can see the tv through it clear as can be and it focuses well, same size 3/8 inch wide line at 14 feet.
But it hardly starts to burn in spots along the line in about 3 seconds then slowly burns the rest of the line.

It is exactly as if much of the output is being reflected, and heat seems to build up faster.

I strongly suspect ar coating burnoff.

EDIT Looking through a jewelers loupe these lenses look like hell, burnt pitted, cooked on trash, they are a wear item, I guess I always knew that. But I have had some that were crapola right from the start. People say o-like lenses are good, but AIXIZ 3 elements have always been the best and they focus at a different distance, I will have to count the turns but I remember doing it before, Slightly tighter dot and the coating is better, the beam looks very clean with the AIXIZ 3 elements. It takes less turns to focus the AIXIZ and that figures, it must be a longer focal length. I will count turns later, I've been up 36 hours.

 

[Pman]

I haven't read back through everything but have a simple question. Is anyone selling these lenses in the US or would I have to order overseas?

 

[RedCowboy]

I haven't read back through everything but have a simple question. Is anyone selling these lenses in the US or would I have to order overseas?

I ordered 3 with the 9mm long housing from podo and I just ordered 4 more in the 5mm long housing with 2-4 day shipping, should be here by Tuesday.

https://sites.google.com/site/hkfew5e22/

Just email podo if you want fast shipping.

 

[Pman]

I don't know why that site doesn't come out right on my note4. Ive had this phone for a year and there's only 2 sites that don't fit right on the screen regardless of whether it's set for mobile or full site. Just a bit annoying. I can look on one of my laptops or desktop though.

 

[RedCowboy]

I got the G7's in the 5mm long housing from podo in 5 business days from China, not bad for only 10 bucks extra on top of the entire order.

The 5mm long housing fits the 9mm diode spring just fine and the threads extend back further giving a better grip on the housings threads.
These fit all our standard 12mm housings with the standard 9mm threads. Note: 1 out of 4 is missing the top ring but has notches, probably an earlier design, it's the top right of the 3 on the left. p.s. Unless you plan to use in a projector you do want the top ring.

When lighting thick kitchen matches with the heads cut off, that is lighting the raw wood the hard way at 5 feet they POP, the focus is like the G2 but divergence is like the 3 element, that is a little rotation makes a lot of difference, but when you get it dialed in it puts down more power than the 3 element, the match sticks don't just light with a NDB7875 like they do with a 3 element at 5 feet, they glow for a second or two then POP out a flame, I mean you hear the POP sound. I really like these, just remember, like the G2 getting a perfect for range focus takes a light touch. With laser glasses on it's easiest to see the focal point against a dark background material, black plastic shows the spot well with any lens, or the already burnt area of your wood target.

Look at how wide open these are, these grab the diodes diverging beam further out, they do the job of the 3 element without as much clipping and loss, I have no problem focusing these without burning my fingers, they have a little lip with grip slots and with a little practice it's not hard to master, I turn it off, adjust, turn it back on until I get it just right. Later I will make an adaptor/thumbwheel, but on the plus, these don't wobble around in the threads.

These are a welcome bridge between the G2 and 3 element with power like the G2 yet a tighter focal point like the 3 element.

Just tell podo if you want the speedpost option, mine got here in 5 days from China and that's not bad.

This video is the G7 in the 5mm long housing at about 15 inches, you can hear the water in the wood pop and fizzle, the 3 element do make a flame kernel, but these are a good 15-20% stronger in my estimation.
This is a NDB7875 diode with the G7 in the 5mm long housing.
If front of the nubm44 it's just instant fire, even not fully focused, but this is the 7875 for testing and comparison.

 

[paul1598419]

I just started reading about this longer focal length lens again and it has renewed my interest in them. Thanks.

 

[RedCowboy]

I put one of these G7's with the 5mm long barrel and wide open lens on the mighty NUBM44 and it's a flamethrower on the wood 15 inches away, even not fully focused it pops out a loud pop and makes me smile

It's hard to see with the flood light out back but the NUBM44 with this lens produces a wider output width ( on the wide axis, that becomes the tight axis )
But at any rate held in the same position the NUBM44 makes a wider beam at the exit with this lens than the NDB7875 with a 3 element.
Somebody with a LPM I hope will give us some numbers, actually podo has some listed for either the NDB or the M near the 1st page.

The beam width at it's exit with this wide open G7 lens is wider than with the 3 element. Very cool. NUBM44 is on the right. This is one of the 3 ring topped 5mm long G7's, I have not tested what I assume is the one old style yet, I don't think it would be much different.

The beam looks good, it actually has some taper when focused to infinity and I don't see the usual 3 element faint wings, but it is a bit foggy this night.

 

[lazeristasUVISIR]

Does this sink get hot/warm at all?

 

[RedCowboy]

It runs for 120 seconds and gets a little warm, 180 seconds and it's still just fine but you can feel the warmth, however it cools down really fast, a lot faster than my big chunk style builds, with a little pc fan behind it you can run until the batteries need a charge, but with 2 x 18650's I charge them to 4.18 and then recharge around 3.7 because of the SXD's minimum input is 6.8v and even INR's sag some under the 44's load.
In short fins are good because they multiply the heat dissipation area, every fin is a heat vehicle.

But on the topic of the G7 lens
Here is a little video of a NDB7875 with the G7 in the 5mm long housing, this is the wide opening lens that I have taken a liking to when burning at 5 meters or so, this video is about 1.3 meters or 4 feet. This is the single element 8mm rear FL G7 in the 5mm housing. Power by a NDB7875 laser diode and 2.4amp Xdrive.
I always wear my safety glasses. THESE MATCHSTICKS HAVE NO HEADS ( Bare wood only )

 

[Moe Ron]

Greetings,

I got my lenses a few days ago, was curious about that holder, how is the lens held in place ? Is it held in place with glue, or is it held in place by friction ?

cheers,
Moe

 

[RedCowboy]

I have not taken one apart yet, I use them as they are, the 9mm long housing with a 9mm spring and the 5mm long housing I use a thicker o-ring in that top groove, it provides the perfect tension for my burning range of 3-15 feet, and infinity focus.

But I would email podo and ask, he should get back to you same day.

Podo's email is :
hkfew5e22@hotmail.com

 

[Moe Ron]

I have not taken one apart yet, I use them as they are, the 9mm long housing with a 9mm spring and the 5mm long housing I use a thicker o-ring in that top groove, it provides the perfect tension for my burning range of 3-15 feet, and infinity focus.

But I would email podo and ask, he should get back to you same day.

Podo's email is :
hkfew5e22@hotmail.com

Greetings,

I don't believe you can take these apart. The lens fits in a groove on the one end and is either pressed and friction holding it in, or glue.
I had bought a few lens holders a few months back from a chinese supplier and they are the same ones as these.
One piece, no O ring or insert to retain the lens. The diameter of the normal G lens is a little too small for that holder also.
I have DTR decanning a diode for me and sent him one to check out.
We'll see what he thinks.... :beer:


cheers,
Moe

 

[RedCowboy]

Greetings,

I don't believe you can take these apart. The lens fits in a groove on the one end and is either pressed and friction holding it in, or glue.
I had bought a few lens holders a few months back from a chinese supplier and they are the same ones as these.
One piece, no O ring or insert to retain the lens. The diameter of the normal G lens is a little too small for that holder also.
I have DTR decanning a diode for me and sent him one to check out.
We'll see what he thinks.... :beer:


cheers,
Moe

Cool.
Do you think you can ask Jordan to run it past his LPM and get a compare against a 3 element?

The G7 seems to let a little more power through, but is has slightly, very slightly more divergence, so it works well at 5 and 10 feet but near the 35 foot limit of these lenses the 3 element with it's slightly tighter divergence comes back into play.

I know podo listed them as passing more of the diodes energy than the 3 element, but not as much as the G2.

I would like to hear a confirmation on those numbers.

Some 3 elements seem to be created better than others, it may just be manufacturing tolerances, but I would like to hear a 2nd set of LPM results.

I still plan to use correctives and expanders for longer work, but numbers are good to know.

Thanks.