Achieving a smaller beam diameter with 803T optics

[Jimmymcjimthejim]

Re: Achieving a smaller beam diameter with 803T op

I'll take some pics.. Tomorrow.
I just finished screwing the lens in, and the batteries ran out of juice .

 

[Krutz]

Re: Achieving a smaller beam diameter with 803T op

I reversed the lens and odd things happened.
To get a parallel beam, you have to screw the lens in all the way. You would think that the dot would be even smaller this way, but it's about the same size. But interesting enough, the odd concentric circle pattern disappeared. Also, the hole of the back of the lens nut limits the size of the beam. I see this because I cut my lens nut to a wide oval shape, and that's the shape of the dot.

sounds good!
so it may be that all objective-lenses do ring-free dots? will have to experiment again as well!
keep up the interesting work! and yes, pics!

manuel

 

[Jimmymcjimthejim]

Re: Achieving a smaller beam diameter with 803T op

[quote author=Jimmymcjimthejim link=1225571544/20#30 date=1227575439]
I reversed the lens and odd things happened.
To get a parallel beam, you have to screw the lens in all the way. You would think that the dot would be even smaller this way, but it's about the same size. But interesting enough, the odd concentric circle pattern disappeared. Also, the hole of the back of the lens nut limits the size of the beam. I see this because I cut my lens nut to a wide oval shape, and that's the shape of the dot.

sounds good!
so it may be that all objective-lenses do ring-free dots? will have to experiment again as well!
keep up the interesting work! and yes, pics!

manuel[/quote]
There's still rings, but you only see them when you unfocus it. When it is a tight dot, there are no rings.

 

[randomlugia]

Re: Achieving a smaller beam diameter with 803T op

I know this thread is kinda old, but I thought I would post this-
http://www.youtube.com/watch?v=S9GjhiFtCa8

It seems that the rounded lens really improved the throw, and the dot was practically the same size 20' away. I can see how this would effect the BR. ;D

 

[Jimmymcjimthejim]

Re: Achieving a smaller beam diameter with 803T op

Thanks for the rep .
I think I will take some pictures of the new beam soon. (With flat side of lens facing diode.)
The only bad part is that it makes the beam an odd shape, but it could improve power.

 

[mikeeey]

Re: Achieving a smaller beam diameter with 803T op

bump!


so has anyone else got this mod working and willing to take some more pics? :

 

[jnrpop]

Re: Achieving a smaller beam diameter with 803T op

Just tried this tutorial and the beam is incridibly thin now, like green dpss thin. the dot is abit disappointing being so scattered but well worth it for a thin beam.
Cant wait till its dark and i can test it out in the sky ;D

Awesome work Jimmymcjimthejim and thanks for sharing!

 

[Spyderz20x6]

Re: Achieving a smaller beam diameter with 803T op

Good mod, but you made it very unclear...
Do you leave the original acrylic lens in there? Or do you take it out completely :-?
Do you put the new lens in the lens retainer that pops out, or the lens nut?
Which lens on the PHR sled?

 

[Jimmymcjimthejim]

Re: Achieving a smaller beam diameter with 803T op

Spyderz20x6,
Read the whole first page.

As per whether the spherical side of the lens should face the diode or not, here is a quick summary:

Facing the diode:
More scatter around the dot
Thinner beam
Worse divergence

Away from the diode:
Less scatter around the dot
Fatter, flatter beam, dot is an odd shape
Better divergence

Right now I have my Sonar with the spherical side facing away from the lens. In order to do this, just follow the tutorial, but flip the back of the lens nut around. (like how it normally is in the Aixiz lens nut, but without the stock Aixiz lens)

Flip this upside down, then insert into the lens nut.

 

[Spyderz20x6]

Re: Achieving a smaller beam diameter with 803T op

Spyderz20x6,
Read the whole first page.

As per whether the spherical side of the lens should face the diode or not, here is a quick summary:

Facing the diode:
More scatter around the dot
Thinner beam
Worse divergence

Away from the diode:
Less scatter around the dot
Fatter, flatter beam, dot is an odd shape
Better divergence

Right now I have my Sonar with the spherical side facing away from the lens. In order to do this, just follow the tutorial, but flip the back of the lens nut around. (like how it normally is in the Aixiz lens nut, but without the stock Aixiz lens)

Flip this upside down, then insert into the lens nut.

Ok, thanks

Also, is the lens you are talking about the front lens in this picture?

http://www.psxboy.com/syssite/home/shop/1/pictures/productsimg/big/804.jpg

 

[Danjoo]

Re: Achieving a smaller beam diameter with 803T op

Yes its that lens!
In dvd applikation you need the short focal lenght to burn the dvd only a few milimeters away from the last lens.

daniel

 

[Jimmymcjimthejim]

Re: Achieving a smaller beam diameter with 803T op

Spyderz20x6:
Yes.
Our goal here is to try to make the lens as close as possible to the laser diode, and actually make it work.

 

[Pavlos93]

Re: Achieving a smaller beam diameter with 803T op

wow Really nice i think I should try it

 

[mikeeey]

Re: Achieving a smaller beam diameter with 803T op

I dont understand why the lens would require sanding down, as small as it already is?
Either way, tomorrow i SHOULD be able to test this out, so ill report back then.

 

[mikeeey]

Re: Achieving a smaller beam diameter with 803T op

obviously I've done something wrong... lol:

I used the smallest lens, with a round side and a flat side. I tried facing both sides towards the diode but it doesn't focus the beam, the light just passes through and makes a circular design.

 

[Spyderz20x6]

Re: Achieving a smaller beam diameter with 803T op

obviously I've done something wrong... lol:

I used the smallest lens, with a round side and a flat side. I tried facing both sides towards the diode but it doesn't focus the beam, the light just passes through and makes a circular design.

I think you tried the wrong lens...