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How painfully bright should the nexus be?
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lathans
25mW Classic Wicked Laser
Joined: 15 Oct 2005
Posts: 33
Location: Norway
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 Posted: 10/30/05, 10:33 PM Post subject: How painfu |
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Hi.
I had my nexus for allmost a week now, and I'm still a little worried that it doesn't output what it should.
I read a lot of posts in this forum, and people say things like that they shined the laser at their white garage door outside in the daytime, and they regret looking at it, and even got a headache because of it, so I expected a very bright light when I was about to push the button when I first got my nexus.
When I first turned it on, wearing my laser goggles, in my living room at the daytime, I thought the dot was very little and not that visible as I expected, so I took of the goggles, and it still looked less brighter than what I expected, and while pointing it around on my carpet, white painted brick wall and even my windows, I started to wonder if the laser had a lower output that it should have.
I made a post at http://forum.wickedlasers.com/viewtopic.php?t=412 to get some input from others.
If I shine it at things like silver coloured equipment (like my tv, tuner, receiver or pc monitor) it is bright, but not so bright that I find it painfull. It's like looking into a light bulb / spot light; it's not good to look at, at least not for more than a few seconds, but you feel fine (at least after a minute or so ;)
I don't feel that the goggles are that necessary unless you plan to look at a bright dot for a longer period of time, or doing experiments where you can get direct reflection (from mirrors or anything like it, NOT just a glass from the kitchen or something).
And this is not just me, as my friends thinks the same.
So... how painfully bright should the nexus be?
Does this sound like the all mighty powerfull nexus?
Either it is not, or if it is, I just had *too* high expectations, because of all my reading on this site/forum...
Just to tell you that my batteries should be ok: I've tried fresh alkaline batteries from duracell (1,57v each, or 3,15v together) and some cheap 800mAh rechargeable Ni-MH batteries (1,32v each, or 2,65v together) with same results using both kind of batteries. The volt measure on the batteries was done with a multi meter before and after inserting them into my nexus (same readings before and after (very short) usage).
My multi meter also says that it draws 0.53A (about 530mA) while operating the laser (with both of the battery types mentioned above). I just unscrewed the battery cap and hold the red pin at the + tip of the battery, and the black pin at the casing of the laser unit to measure this without opening or tampering with the unit in any way.
Measuring the volts of a green LED while shining the nexus right into it says 1,678 volts with either of the battery types, so I guess the output is pretty much the same no mather what batteries I use, as long as they are fresh enough. This varies of course slightly from one LED to another, even if they look just the same.
Btw, please consider to help me identify that my nexus is anywhere near 95mW instead of giving me laser safety lectures when replying to this post:)
Thanks!
--
What's the difference between a light bulb and a pregnant woman? You can't unscrew the woman... |
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Athoul
Wicked Lasers God
Joined: 13 Sep 2005
Posts: 7544
Location: Canada
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| Posted: 10/30/05, 10:51 PM Post subject: |
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Although you don;t want a safety lecture I have to clarify some points you mentioned.
PLEASE don't tell me you looked at it off of shiney surfaces???, a GLASS from the kitchen can reflect the laser just as a prism!!! and make you blind in less the a millisecond(anything metalic/polished/silvered/etc counts). There is no safe duration to look at the laser off of these surfaces, without safety goggles on.
The dot is not painfully bright to me either, but to some people it is. This in no way however is a measure of how dangerous the beam is. There are no pain sensors in your eyes, you will get no warning of damage. The damage from a Nexus laser to your eyes can and most likely WILL be permanent.
I'm sorry but I had to post this..as you are in serious risk of causing yourself permanent eye damage.
Now for power of the laser.
We can narrow it down through some easy experiments. To get a rough ballpark figure for where your laser sits.
Have you tried poping a red balloon? This laser will be able to pop them.
Have you tried to burn black electrical tape?
if so does it burn through or at least smoke? (it should at least smoke) it takes at least a >50mW or so to make
thin electrical tape smoke.
Does it feel warm when you aim it into the palm of your hand?
it should feel warm. To get warmth is a sign of significant output.(probably around 60mW and up to start feeling any warmth.)
Does it get black leather to smoke?
This is another sign of significant output, it takes around >70mW or more to usually do this.
You said you were successful with this in your other post.
Forget about the match test, it's to hard to do to get an estimate on output.
Try these and let me know.
Do you have any other green lasers? If you do, then you can try the LED test to compare them. You might not get an accurate mW reading, but you will get an accurate difference in power between the two. Eg, if you had a 10mW then the measure for the nexus should be 9-10 times that, unless the 10mW is over or under powered.
Last note.. please take what I said in the first couple paragraphs seriously, you really don't want to risk your vision over something that could so easily be avoided.
cheers,
Sean.
Last edited by Athoul on 10/30/05, 11:07 PM; edited 1 time in total |
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nero_design
Wicked Lasers God
Joined: 02 Sep 2005
Posts: 1463
Picture(s): 98
Movie(s): 1
Location: Australia
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| Posted: 10/30/05, 11:01 PM Post subject: |
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I think one of the easiest test to run (for those of you without a laser power meter) is to hold your laser to a black leather belt or a black leather wallet etc and turn it on for about 5 seconds. To be sure the laser is steady, you can rest the edge of the front brass fitting against the surface first but allow room for the smoke to escape and avoid allowing the smoke to enter the aperture....If the laser is over 90mW/100mW, the leather will emit a tiny wisp of white smoke within 1.5 seconds. If it takes any longer than 2 seconds, then the laser may be under powered or less than 90mW.
The dot in daylight is not much more different than other laser powers although it will have a slightly larger corona. In night time, the dot emits so much light that you can illuminate a room when the laser is turned onto a light coloured surface such as a white ceiling.
_________________
Regards,
Marco Nero
* Laser Gallery: http://www.pbase.com/nero_design/pro1wickedlasers
* Always use appropriate laser-safe eyewear when using higher powered lasers. |
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lathans
25mW Classic Wicked Laser
Joined: 15 Oct 2005
Posts: 33
Location: Norway
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| Posted: 10/31/05, 1:17 AM Post subject: |
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Athoul: Sorry that I didn't specified that I did this in a lot safer way than it sounds in my post...
I did this by first wearing the goggles, and I looked the other way to see what kind of reflections there was, and I noticed that it was _very_ spread, as I couldn't see anything on the wall behind me except for a slight glow of green spread out over the whole wall (about 4 meters from where the laser hit the surface), and I tried holding a white paper in the middle of the wall and the dot to see how much it lit up.
Of course, I took well care not to be looking at a consentrated reflection (which I was unable to make, at least which still was consentrated over several meters, not even with the kitchen glass (at least not this one)).
As I said, I have read many posts in this forum, so I have read quite a few warnings too;)
I have always and will always wear goggles while pointing at anything close to me, or at surfaces I don't know how reacts.
But yes, I was standing 3-4 meters from my TV and pointed the beam at it's silver casing, in an angle that wouldn't reflect back to me, but give a very bright dot, still after taking several precautions.
Thanks for the warning anyway. I guess it can't be too few of them in this forum.
About trying other lasers with the green diode... I since I measure 300 to 620 mV with my unstable <5mW leadlight, I don't think the volt readings are like twice the laser output, twice the voltage.. and so on.
It get black leather (and even black rubber and some plastic types too) to smoke pretty fast, so it sounds like it's good enough.
I will buy some black tape and some balloons today, and report back with some results:)
Thanks for the info, both of you! |
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Athoul
Wicked Lasers God
Joined: 13 Sep 2005
Posts: 7544
Location: Canada
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| Posted: 10/31/05, 2:30 AM Post subject: |
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It's not the mV you want, it's the mA. Use a multimeter set to milliamps. tell me the numbers you get, it should read as 0.XXX... mA. Post the numbers you get here.
cheers, |
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lathans
25mW Classic Wicked Laser
Joined: 15 Oct 2005
Posts: 33
Location: Norway
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| Posted: 10/31/05, 3:00 AM Post subject: |
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I tried measuring milliamps and even microamps, but I couldn't get any reading at all (0.00)
Are you sure this should work? ...I mean, since measuring amps directly on the pins of a diode will short it... |
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Athoul
Wicked Lasers God
Joined: 13 Sep 2005
Posts: 7544
Location: Canada
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| Posted: 10/31/05, 3:16 AM Post subject: |
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ok here is what you do.
1. Set the multimeter to mA
2. Hook the Negative lead of the multimeter to the Cathode lead of the LED, then hook the positive lead from the meter to the anode of the LED. Trust me, you want this so that the light will generate current.
3. Have the head of the LED up resting on the hole in the laser aperature.
4. Turn on the Laser and read the results...move the LED till you get the highest reading. Run for about 10-20 seconds to get an accurate reading. You will see an initial spike for a second or so, then it will drop to a sustained figure. This sustained figure is what will help figure out the constant power. The initial is what will help us figure ot the aproximate initial startup power.
5. Repeat on other laser.
6. Post the results here. 
cheers, |
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lathans
25mW Classic Wicked Laser
Joined: 15 Oct 2005
Posts: 33
Location: Norway
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| Posted: 10/31/05, 4:01 AM Post subject: |
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My bad! I had to use another connector for amperes below 200mA. I usually only use the "10A" mode.
Good thing that I happen to know what the cathode and anode of a diode are, so I didn't have to feel stupid when reading your post:P
Anyhoooo, it reads around 28.5 (with a starting peak of around 40.0) in the display when I set the multimeter to 200 µ (mu aka micro). I don't have the manual for this multimeter, so I don't know if that's 28.5 microamps, or what.. if that's the case, it's 0,028 mA
The leadlight <5mW reads out 1.4 with a starting peak around 2.0.
So the nexus gives about 20 times what the <5mW leadlight does.. that doesn't sound too bad, considering 5mW is 1/20 of 100mW..
I tried with a second green diode.. same results..
I tried with a third green diode.. hey! New results!
Nexus reads around 185, and the leadlight about 7. That's even better results for the nexus compared to the leadlight one.
It was very unstable reading on both lasers with this diode. The Nexus went from 100 to 190, but sometimes it was somewhat stable around 185.
I'll post pictures of the diodes in a moment... the third one looks a little bit different from the first two. |
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lathans
25mW Classic Wicked Laser
Joined: 15 Oct 2005
Posts: 33
Location: Norway
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Athoul
Wicked Lasers God
Joined: 13 Sep 2005
Posts: 7544
Location: Canada
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| Posted: 10/31/05, 4:19 AM Post subject: |
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Your first two readings looks pretty good to work with, here is what I calculated based on that. We will drop off any points.
Also what we want is a number that the laser is on most of the time, any other number and you will not have a accurate level of difference. Note this methid is not 100% accurate but it will demonstrate the difference between your Nexus and your 5mW.
Your Nexus works out to this. 0.28 x 1000/2.8 = 100mW
Your 5mW would be 0.014 x1000/2.8 = 5mW
Is your 5mW from Wicked?
In conclusion the mW results may be off by up to 20%, however what is definate is that your Nexus is aprox 20 times as powerful as your 5mW. |
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