Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

405nm Pen from Etimeshop (Ebay)

Joined
Sep 4, 2008
Messages
1,808
Likes
32
Points
0
I think he expected the bottom to screw off for the battery, instead of the entire thing screwing in half (as all of the Newwishes do).
 

jbtm

New member
Joined
Mar 22, 2010
Messages
495
Likes
30
Points
0
Yep...I never seen lasers screw apart at the middle. This is my first. I wish the front metal cap came off to adjust the lens. Comparing to my 5mw red pens, the laser dot is a bit larger on my violet laser. Almost by twice the size. I'm going by a guess but at 2" the dot is about 3.5 - 3.9mm, going off the dots reflection with a caliper. My red laser, The cap comes off and you can easily adjust the lens. I'm guessing the violet laser is glued in, or pressed.

I noticed if you look into the aperature (hands off the laser) the lens inside looks yellow'ish...None of my lasers do this :p
 
Joined
Sep 4, 2008
Messages
1,808
Likes
32
Points
0
It could look yellow because it uses an AR lens for 405nm, but I highly doubt that would be included in such a cheap laser. As for the beam, I must have gotten a good one... I have seriously never seen divergence this good. Are you observing the dot size from a distance? As you probably know by now, this wavelength is really hard to focus on, even for cameras. PS... You can change your signature now.

EDIT: Well, I just went to do a divergence test. But is was difficult, because the beam is actually SMALLER at ~15 feet than it is at the aperture! Yes, I am sure of this. I guess these lasers are pre-focused around 15 feet. I'll do a bigger test after it gets dark.
 
Last edited:

jbtm

New member
Joined
Mar 22, 2010
Messages
495
Likes
30
Points
0
No, from 2" away it was estimated 4" diameter using glasses that diffuse it to look whitish. So no glare. At about....20ft (by a guess!) the diameter is 3.46mm I redid a measurement for 2" and it's actually ALMOST the exact same. My point was just the fact that my 200mw green and 5mw red laser has a smaller diameter dot...As my bluray i felt was wider. Must just be the lens they used. As you stated, these have VERY good divergence, as I almost want to say it was the exact same from 2" to 20ft.
 
Joined
Sep 4, 2008
Messages
1,808
Likes
32
Points
0
Usually fat beam = good divergence. Mine's probably about 3.5mm also. Do you have a GITD board yet?
 

jbtm

New member
Joined
Mar 22, 2010
Messages
495
Likes
30
Points
0
I'm sorry but I dont know what a GITD board even is ;) So id have to say no...No way to measure the beam mw output either
 
Joined
Sep 4, 2008
Messages
1,808
Likes
32
Points
0
Glow in the dark?



They are so much fun.
I picked up a can of glow in the dark spray paint for $7, and just sprayed a wooden board with it. It's a necessary piece of equipment for any blu-ray owner!
 

jbtm

New member
Joined
Mar 22, 2010
Messages
495
Likes
30
Points
0
Oh...I must get one. I only have a 3" wide star! I'll remember to get some...Maybe use that foam poster board for cheap 3x4ft glow board :) Willl do!!!! Glow spray is that good i take it? To hobbyworld!!! If only they had a material that glowed for 5 mins or more...Etch-A-Sketch laser style...
 
Joined
Sep 4, 2008
Messages
1,808
Likes
32
Points
0
If your eyes are totally adjusted to the darkness, this stuff will still be glowing faintly about 3-4 minutes later. I use the paint made by Valspar.
 

Pontiacg5

New member
Joined
Dec 23, 2007
Messages
2,524
Likes
166
Points
0
This laser has a boost driver (obviously) that is very respectable looking. I hope to have some pics and specs of it soon. They might be a good source of drivers for diodes needing a lower current.

I'll post pics tomorrow :D
 
Joined
Jun 24, 2009
Messages
365
Likes
18
Points
0
...because the beam is actually SMALLER at ~15 feet than it is at the aperture! Yes, I am sure of this. I guess these lasers are pre-focused around 15 feet...
Thanks for the tip. I did all my divergence tests from 5 ft away... i'll try this from 15ft to see if I get a tighter beam at that distance. I have two BR pen from two different chinese resellers. I'll have to see if there's a difference between the two.
- Robert
 
Joined
Sep 4, 2008
Messages
1,808
Likes
32
Points
0
This laser has a boost driver (obviously) that is very respectable looking. I hope to have some pics and specs of it soon. They might be a good source of drivers for diodes needing a lower current.

I'll post pics tomorrow :D
Wait, wouldn't you not want a boost driver for lower current diodes? I'm confused, it seems to me that they would need less current, not a boost... But then again I'm not a DIY guy.
 

Eudaimonium

Well-known member
Joined
Feb 5, 2008
Messages
6,310
Likes
447
Points
83
Wait, wouldn't you not want a boost driver for lower current diodes? I'm confused, it seems to me that they would need less current, not a boost... But then again I'm not a DIY guy.
Boosting voltage, not current, is what we are talking in boost drivers, which are also commonly called DC/DC converters,
Basically, all bluray type diodes work on around 5 V, but you might have noticed we use 2x AAA to power these.
There is a driver which performs the conversion of two values, Current and Voltage, for suitable applications.

For instance, my boost driver in my GGW build, uses 350mA from 3.7 V battery, to get 190mA at 5 V on the output (to the diode).
 

jbtm

New member
Joined
Mar 22, 2010
Messages
495
Likes
30
Points
0
I did do a 2 sec exposure to increase the brightness...But I got it from hobby lobby. Lemme tell you that personally I felt this was the worst spray paint I ever bought. I held it for over 5 mins to do small areas because it came out so horrible, I was getting more air than paint and I even got sick of it, shook it a lot for 3 mins, and it still sucked. Next time I'll try my local hardware store, Gemmens...

Hobby lobby sells it in a ~6 x 2 inch mini'ish can. I spray painted foam board, with a paper matt...So it did bend a bit.
 




Top