Old 10-29-2016, 08:26 PM #1
Member
 
Join Date: Jun 2010
Location: SF Bay Area, California, USA
Posts: 41
Rep Power: 0
bluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond repute
bluestars bluestars is offline
Member
 
Join Date: Jun 2010
Location: SF Bay Area, California, USA
Posts: 41
Rep Power: 0
bluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond reputebluestars has a reputation beyond repute
Default Improving Focus

Hello all,

Back in 2011, I bought a 445nm ~1W laser from an LPF member. It runs on a 14500 and is built in a little Trustfire F25 host (flashlight review for some detailed pics of the host). It's a sweet little laser, but my needs have changed. In 2011, I was more interested in burning. Five years later, I like nice beam specs - narrow and low divergence. This laser is focusable, but when the focus ring is screwed all the way down, it does not focus to infinity. Instead, it seems to focus "beyond" infinity (whatever that means). I don't understand the optics well enough to know what is happening, so let me describe:
When I screw the ring all the way down, the beam seems to spread quite widely, even when I'm sky-pointing. If I unscrew the ring just a little bit, it seems to be more collomated.

So... what does it mean for something to be focused "beyond" infinity? And is there anything I can do to fix this? I'm pretty sure that it's using an Aixiz lens.

You can see some of my photographs of the laser in this album. I'll try to grab some beamshots that demonstrate my issue tonight.

Thanks!


__________________
500mw 405nm eBay labbie
1W 445nm built by yobresal
Uniphase-Cyonics 2201-25ML 488nm+ Argon
Sanwu 304 80mW 532nm
Gammax 1A415 1mW 632.8nm HeNe
LPC-826 250mW 658nm labbie (waiting for heat sink and driver)

Last edited by bluestars; 10-29-2016 at 08:27 PM.
bluestars is offline   Reply With Quote










Old 10-30-2016, 01:08 AM #2
Sta's Avatar
Sta Sta is online now
Class 3R Laser
 
Join Date: Jan 2014
Location: New Jersey, USA
Posts: 1,636
Rep Power: 4891
Sta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond repute
Sta Sta is online now
Class 3R Laser
Sta's Avatar
 
Join Date: Jan 2014
Location: New Jersey, USA
Posts: 1,636
Rep Power: 4891
Sta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond reputeSta has a reputation beyond repute
Default Re: Improving Focus

Focusing beyond infinity is normal -- it happens with almost every laser if you put the lens too close to the diode. This is because the beam has not spread out enough to be properly collimated by the lens. So it's perfectly normal to have to unscrew the lens a bit.

__________________

403nm BTB LP405-5
405nm "5mW" eBay pen, 50mW 'bottle' pointer, 450mW lmlaser
445nm 7W NUBM44 lightsaber build
450nm 2W SF501B, 10mW pointer, 50mW lmlaser
453nm 100mW LaserBTB HL
455nm 1.6W Arcane
457.9nm Argon line
470nm NUBM07E S4X build
473nm 100mW PL-E Pro, LG Aquarius-2
476.5nm Argon line
488nm Argon line
496.5nm Argon line
501.7nm Argon line
513nm 50mW Thor
514.5nm Argon line
515nm 200mW 501B
522nm 1.4W S4X build
527nm
532nm 500mW XPL-H, 2x gearbest, 9-line 301, 35mW lmlaser, LG Anser-5
537nm
542nm
543.5nm Gammex HeNe
547nm
561nm 50mW PGL-III-C
583.8nm Spartan primary cold line
586.2nm
589nm 120mW PGL-III-C, DL Spartan (7+ lines) 177mW pk!
591nm
593.5nm Rigel-6, LaserCentury Y3PL-T8 20mW
594.1nm LHOR-0150M HeNe
604nm LHOR-0150M HeNe
609nm LHOR-0150M HeNe
612nm LHOR-0150M HeNe
632.8nm 10mW JDSU HeNe, 10mW Lasos HeNe
635nm 90mW DL Spartan, LG Libra
638nm 600mW XPL-310
655nm BTB LP650-5
660nm 200mW (3x), "5mW" eBay pen
690nm 15mW module





YouTube - Starmute VII!
Sta is online now   Reply With Quote
Old 11-01-2016, 03:41 AM #3
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,086
Rep Power: 5472
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,086
Rep Power: 5472
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Improving Focus

There's no such thing as "beyond infinity". It's either focused, collimated (focused to infinity), or not focused. If the beam doesn't come to a point at any length along the beam path, that means the lens is too close. If it comes to a point and diverges again, that means the lens is too far.
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 11-01-2016, 10:30 PM #4
Class 3R Laser
 
Join Date: Jun 2007
Posts: 1,439
Rep Power: 3069
steve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond repute
steve001 steve001 is offline
Class 3R Laser
 
Join Date: Jun 2007
Posts: 1,439
Rep Power: 3069
steve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond repute
Default Re: Improving Focus

Quote:
Originally Posted by Cyparagon View Post
There's no such thing as "beyond infinity". It's either focused, collimated (focused to infinity), or not focused. If the beam doesn't come to a point at any length along the beam path, that means the lens is too close. If it comes to a point and diverges again, that means the lens is too far.
There is, but it doesn't mean what it sounds like. It means infinite conjugation or more simply the optimal minimum divergence.
Reply to the red text. That also indicates the lens has collimated the beam optimally, or focused to infinity (and beyond!)
steve001 is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading












Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 10:08 PM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC