"Correcting" Blu Ray Dot

[LarryQ]

I don't know if anyone has asked this question before, but I was wondering if there is a way to "Correct" the dot from a Blu-Ray so that it does not look like a center dot with a bunch of dots surrounding it.

My first guess is that there is something going on with the lens/ coating of Axiz and Merridith modules....

I have tried both glass and acrylic, and nether of these seem to make any diff in the dot.

Thanks

Larry

 

[daguin]

Read the stickies

http://www.laserpointerforums.com/forums/YaBB.pl?num=1219161671

If the lens and the window are clean, all you can easily do is shine it through an aperture. If you have opened up the back of the lens (or got it already opened), replace it with one that still has the aperture in place.

Peace,
dave

 

[LarryQ]

I had read those stickies.....

I have been thinking about what the dot would look like with AR coatings specificly for 405 (or so) nM.

Because the outside dots seem so symmetric around the center point, there has to be something going on with the lenses we use at this frequency

Has anything ever come of IgorT's custom lenses???

Larry

 

[ElektroFreak]

I'm not really sure exactly what you're describing. None of my blu-rays have a ring of smaller dots surrounding a larger center dot.. Post a picture if possible..

 

[daguin]

I had read those stickies.....
I have been thinking about what the dot would look like with AR coatings specificly for 405 (or so) nM.
Because the outside dots seem so symmetric around the center point, there has to be something going on with the lenses we use at this frequency
Has anything ever come of IgorT's custom lenses???
Larry

The "halo" and "ghosts" around the beam can be very symmetrical. Make sure that the lens and window are clean and undamaged. After that all you can do is physically limit the "side reflection" in the beam (with an aperture). The AixiZ and the Merideth give VERY different beam patterns.

IgorT is still working on getting the funding he needs together for the lenses.

Peace,
dave

 

[deam_87]

mine does that too, but i think its because u cant really focus on the dot at that wavelength. at first, i also thought it was the lens, but i figured it wasnt when i rotated the laser pointer in my hand and the dots surrounding the bigger dot in the middle just stayed fixed on the wall and didnt spin.

 

[jander6442]

mine does that too, but i think its because u cant really focus on the dot at that wavelength. at first, i also thought it was the lens, but i figured it wasnt when i rotated the laser pointer in my hand and the dots surrounding the bigger dot in the middle just stayed fixed on the wall and didnt spin.

Sounds to much like the window on the diode that is the obvious solution.

 

[jander6442]

I've seen some lens housing that I have gotten from hightech that either intentionally had a pin hole behind the lens that would
limit the side "scattering" in theory. Maybe this was done in the manifacturing process as an oversite. I should take a pic for all to see.
the thing is I should have done some swapping from pointer to pointer to see if there was a differance. I am having problems just making time to have fun with my units let alone lens comparison. God bless those people having the time for real investagative
research.

 

[proud2deviate]

The halo of smaller dots is an illusion. You can't get rid of it.

If you point your laser at a far wall, you see the halo around the dot, right? Now, leave the laser where it is, and approach the dot. The halo disappears when you get close to it.