Laser Genetics Genisys ND3 (Large Pics)

[ossumguywill]

I have a feeling either I or you don't understand each other.

At 3ft away from the laser....I could make the beam/dot 26mm+ or less than 1mm like so.

It was the same way at 25ft away as well.
It just depended on how I adjusted the focus. The focus has a huge range.

according to the flash animation, the laser does not focus to have negative divergence (focus to a point), it only focuses out and very close to 0 divergence. So you could not, say, burn things with this laser because the minimum beam width is no thinner than at the aperture.

will

 

[iskor12]

according to the flash animation, the laser does not focus to have negative divergence (focus to a point), it only focuses out and very close to 0 divergence. So you could not, say, burn things with this laser because the minimum beam width is no thinner than at the aperture.

will

The flash video does show that for the ND5.....But I swear to you that this is not true for the ND3. If this laser had a stronger module in it....it would be a massive burner.

The ND3 will focus to have negative divergence....this is why I say that measuring the divergence is pointless.

Here is a picture of the first beam shot that I took with this laser. If you look closely at the beam, you will see what I am talking about.

Here is another one. I didn't post this one because it was way out of focus....but you can clearly see the beam getting smaller ater it exits the aperture.

 

[ossumguywill]

The flash video does show that for the ND5.....But I swear to you that this is not true for the ND3. If this laser had a stronger module in it....it would be a massive burner.

The ND3 will focus to have negative divergence....this is why I say that measuring the divergence is pointless.

Oh my bad.... LOL I wasn't really paying attention and I forgot I was talking to the guy who did the review LOL. I just assumed it would be the same unless you said differently, little did I know that's exactly what you did.

will

 

[iskor12]

Oh my bad.... LOL I wasn't really paying attention and I forgot I was talking to the guy who did the review LOL. I just assumed it would be the same unless you said differently, little did I know that's exactly what you did.

will

It's all good.

FYI: Look at the pictures in my previous post for reference.

 

[steve001]

The flash video does show that for the ND5.....But I swear to you that this is not true for the ND3. If this laser had a stronger module in it....it would be a massive burner.

The ND3 will focus to have negative divergence....this is why I say that measuring the divergence is pointless.

Here is a picture of the first beam shot that I took with this laser. If you look closely at the beam, you will see what I am talking about.

Here is another one. I didn't post this one because it was way out of focus....but you can clearly see the beam getting smaller ater it exits the aperture.

Ok, both pics show negative divergence. But negative divergence ain't what I find interesting. Since this device can be focused there has to be a position of optimal collimation. Adjusting the bezel will create a beam that to the eye looks to have parallel sides. That's the position of optimal divergence and the point I'm interested in. It comes down to my curiosity to know what the Rayleigh Range is for this device which is unknown at this time. And what the divergence is for this device once the beam passes beyond the Rayleigh Range. I'm fairly certain it is well beyond 25 feet.

 

[iskor12]

You lost me on the whole Rayleigh Range thing.

Also, please keep in mind that I do not have this laser in my possesion anymore.

Also...wouldn't trying to make it visually parallel and then measuring it....still have the human error influence?

 

[steve001]

You lost me on the whole Rayleigh Range thing.

You've never heard of the Rayleigh Range-ok ?
Rayleigh Range (aka Rayleigh Length) is the distance over which the beam will expand *1.4 times it's original diameter. More specifically it's the distance over which the optics make the beam converge at nearly the same rate the beam wants to expand do to the diffractive property of light waves. Keep in mind that any laser beam does not expand at it's specified mrd rating until it passes beyond the Rayleigh Range.

* For this device lets say the Rayleigh Range is 91.44 meters ( 300 ft) Multiply beam dia 26mm ( =1in.) x 1.4 will give you a beam diameter of 36.4 mm (= 1.4 in.)

Also...wouldn't trying to make it visually parallel and then measuring it....still have the human error influence?

You actively measure the beams diameter (or spot size) starting at 10 meters. I've done this before using picture frame glass marked in X Y millimeter increments. The measurements would only be approximate which is good enough.

Also, please keep in mind that I do not have this laser in my possesion anymore.

If you do get the chance I'd still like to know.

 

[vitalyx]

Nice and thorough review! You are right about this thing being too expensive.
If someone needs anything like this for cheap, I would suggest taking a DX module and putting it without a focusing lens into a rayfoss waterproof host with reamed aperture. Total investment is just above $25.

This is a pot modded 5mW DX module with focusing lens removed:

 

[iskor12]

Thanks.

Nice tip....however this thing has adjustable focus and it will also throw the beam much further than what a dx module or any other module would. The beam expander makes the difference.

 

[ossumguywill]

Thanks.

Nice tip....however this thing has adjustable focus and it will also throw the beam much further than what a dx module or any other module would. The beam expander makes the difference.

Why is it that wider beams go farther? I can't really see how a wider beam makes it any better than a well-focused thin beam. Care to explain?

thanks,
will

 

[iskor12]

This is how I picture it....Please keep in mind that I may very well be wrong.
Please, if I am wrong, let me and other people know. Thanks.

Laser on the left is (Normal) Laser on the right has a beam expander and is focused to have a small dot at 300ft

 

[ossumguywill]

This is how I picture it....Please keep in mind that I may very well be wrong.
Please, if I am wrong, let me and other people know. Thanks.

Laser on the left is (Normal) Laser on the right has a beam expander and is focused to have a small dot at 300ft

good explanation-thanks

will

 

[steve001]

good explanation-thanks

will

The graphic only tells some of the story. This explanation is correct if you are focusing the laser. But focusing is not what you'd want to do if the goal is to achieve minimal divergence
[ optimal collimation ]. Optimal collimation is focusing the laser to infinity. Not a point at some predetermined distance. What a beam expander really does is flatten the curvature of the light waves. This causes the light waves not to spread as quickly as they would without being expanded. Were the graphic falls short is not showing what the irradiance will be at great distances. In that case the power will be greater compared to an unexpanded beam because the beam has a lower divergence.

 

[ossumguywill]

The graphic only tells some of the story. This explanation is correct if you are focusing the laser. But focusing is not what you'd want to do if the goal is to achieve minimal divergence
[ optimal collimation ]. Optimal collimation is focusing the laser to infinity. Not a point at some predetermined distance. What a beam expander really does is flatten the curvature of the light waves. This causes the light waves not to spread as quickly as they would without being expanded. Were the graphic falls short is not showing what the irradiance will be at great distances. In that case the power will be greater compared to an unexpanded beam because the beam has a lower divergence.

not sure I get it, but are you saying that it's easier to make the sides of the beam perfectly parallel with an expanded beam?

will

 

[steve001]

not sure I get it, but are you saying that it's easier to make the sides of the beam perfectly parallel with an expanded beam?

will

No, I'm not. 0 divergence is not possible.
What I'm saying is an expanded beam will have a flatter wave over an unexpanded beam. Less curvature mean the divergence of the beam will be lower.

 

[ossumguywill]

No, I'm not. 0 divergence is not possible.
What I'm saying is an expanded beam will have a flatter wave over an unexpanded beam. Less curvature mean the divergence of the beam will be lower.

I'm not really sure what flatter wave means. That's where I'm hung up.