10 meters is likely enough distance to measure beam divergence. I doubt the Rayleigh Range is greater than 10 meters. Use a mirror to double the distance. Since the beam is 4mm at the aperture and 3mm at 10 meters the beam as you know is being focused. Make the spot size match the beam diameter at the aperture.The Sale
Recently i have been getting back into lasers and with all these new laser wavelengths coming out i kept my eye out for them. This past Saturday i stumbled across this awesome 495nm laser build by Lifetime17. I payed on Saturday, it shipped Monday and i received it today. Crazy fast.
The Close ups
20180124_193730 by Alex Littig, on Flickr
20180124_194057 by Alex Littig, on Flickr
20180124_194042 by Alex Littig, on Flickr
20180124_194003 by Alex Littig, on Flickr
20180124_193941 by Alex Littig, on Flickr
20180124_193903 by Alex Littig, on Flickr
20180124_193412 by Alex Littig, on Flickr
20180124_191514 by Alex Littig, on Flickr
I think its safe to say the machining work from Lifetime17 is beyond top notch. Not a single flaw. The threads are super smooth, the 14500 battery fits perfectly and the momentary button feel is very premium. The host is absolutely perfect.
Beamshots(WARNING PIC HEAVY) After playing with some camera settings i managed to get the color on the photos to match what i see with my eyes. At least as close as i could.
20180124_194445 by Alex Littig, on Flickr
20180124_194655 by Alex Littig, on Flickr
20180124_194615 by Alex Littig, on Flickr
20180124_184538 by Alex Littig, on Flickr
20180124_191248 by Alex Littig, on Flickr
532nm, 495nm, 445nm
20180124_194918 by Alex Littig, on Flickr
(532nm vs 495nm)
20180124_191906 by Alex Littig, on Flickr
Divergence
So when it came down to measure the divergence it was not really possible. I only have 10 meters to work with inside my apartment. The beam diameter coming out of the aperture was 4mm and the beam diameter at 10 meters was 3mm so it was getting smaller which means i am not far enough away to properly focus this laser to infinity. Also i am trying to abide by the duty cycle as much as i can and if i really want to measure the divergence properly ill need a about 30 meters and another person. Just goes to show how insanely awesome the divergence is. id say its the lowest divergence laser iv ever seen. even better then the BDR-209DBK 405nm diode.
ppppppppppppppppppppppppppppppppppppppppp by Alex Littig, on Flickr
LPM Measurement Graph
I try to keep the duty cycle around 30 seconds as instructed by Lifetime17 but my lpm has a longer response time so i put the laser near a cool window and lit it get fairly cold. maybe 60 degrees F. After the minute test it was still cool. No problem at all. I think my meter reads low as there are a few burn marks on the sensor and Lifetime17s much higher quality lpm reads a bit higher.
495nm laser review by Alex Littig, on Flickr
Conclusion
This laser is my dream laser. This wavelength is want i dreamed about back when the first 445nm where coming out and now its a dream come true !!! The color is stunning. The beam is so brilliant especially with fog and what i like is its only 100mw so its fun to use and i dont have to worry about burning holes in things. I would like to give a huge thanks to Lifetime17 for this laser. It truly is a masterpiece.
That spot looks like there's dirt on the lens.
A few questions. Why that size battery? Do you happen to know the focal length of the lens?