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What if I Don't Have an LPM?

Belch85

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If all lasers (of different power outputs) produced the same affect on substances around us; then there would be no measurable difference of effect. There would also be no need to purchase any laser of a different strength (as one 5mW laser would suite all applications).

Since there is a measurable difference of affect by different powered lasers - there is a subsequent need to purchase different strength lasers for different applications. Since these different lasers produce a different affect on the substances around us; the difference of effect is measurable. Since it is measurable; statistical estimations can be made. These estimations may be of very low accuracy; or of very high accuracy - but the fact stands - that they can be made.

I'm done

See if any of you can make him understand

He doesn't want to believe me

Peace,
dave
Dave - I am not attacking you. It is not you that I am choosing to believe or not believe. I have a brain; with a logical ability - and I'm applying it to the laser knowledge I have. When I do this; I come up with a only slightly different message than the one you are conveying. If you have the time, I would really appreciate your input through a constructive response - that can help me (not make me) understand further.

Kind Regards,
Belch85
 

daguin

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If all lasers (of different power outputs) produced the same affect on substances around us; then there would be no measurable difference of effect. There would also be no need to purchase any laser of a different strength (as one 5mW laser would suite all applications).

Since there is a measurable difference of affect by different powered lasers - there is a subsequent need to purchase different strength lasers for different applications. Since these different lasers produce a different affect on the substances around us; the difference of effect is measurable. Since it is measurable; statistical estimations can be made. These estimations may be of very low accuracy; or of very high accuracy - but the fact stands - that they can be made.



Dave - I am not attacking you. It is not you that I am choosing to believe or not believe. I have a brain; with a logical ability - and I'm applying it to the laser knowledge I have. When I do this; I come up with a only slightly different message than the one you are conveying. If you have the time, I would really appreciate your input through a constructive response - that can help me (not make me) understand further.

Kind Regards,
Belch85
You *want* to believe something that you *feel* is right
I cannot argue against wants and/or feelings

Have a nice day

Peace,
dave
 

ZRaffleticket

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Thing is, there's not really any accurate way to measure a laser's power without an LPM.

Things like wavelength, room temperature, and beam size all have to play into it. If you're trying to estimate a 1.2W to 2.2W 445nm laser (as Dave said), there's not much room to estimate because that kind of power already annihilates everything. A 200mW deviation isn't enough to make any significant advances in annihilation.

If you want to go by brightness, it's all subjective. Yes the beam is visible, but there's no accurate way to measure how visible a beam is. It's as bright as a dim flashlight. Well how bright is that? That said, how bright is 10 lumens?

There's no guide for the 445's because most people get them LPMed, If you want to create a guide, go ahead. Just don't try measuring it with your lips.
 

Cyparagon

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I think Mr. Belch is saying we can estimate laser power, but with rather poor accuracy. I agree in a sense. However, I'll assert the accuracy is so poor that it is virtually useless. Brightness will only get you so far, because there are many, MANY factors that will skew that.

Your stock trichromatic ocular devices will only give you comparative measurements (this dot is brighter than that dot), and only if the difference is more than 10% or so. This totally useless across colors, because as you know, some colors are brighter than others.

Maybe a seasoned professional that has dealt with lasers for a few decades might have a chance at guessing +/- 20%, but he will have had lots of access to power meters to begin with.
 

Belch85

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Thanks for your valuable input ZRaffleticket & Cyparagon. Both posts have helped me to think about this further (and gain a better understanding). Admittedly I often don't deal well in the face of absolute rulings; and probably have spoken well outside my scope of understanding. I hope we can all get along in our love for lasers.

I guess my main point is/was:
"If you don't have an LPM, here are some friendly suggestions that may help you guess - but by no means are these methods definitive and accurate, and if you plan to X, Y, Z with your output power figures then you really do need to get it LPM'd. The reason it is so hard to guess a lasers power is: X, Y, Z. While you can estimate that a laser is above X power by testing it with Z, you cannot differentiate between A, B or C power outputs easily using any of these methods. While you can test using X method for Y, you will find it only accurate up to point Z."

Perhaps I should have asked nicely for a bit more information, and done some research, and tried to come up with some of this information myself. This is all fun and I enjoy learning.
 
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norbyx

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Well one thing is for sure, a LPM is the best thing you can buy if you plan in sticking with this hobby. For many reasons.
Anyhow just FYI, the WL kripton in low power mode gives about 100mw tops and a Skylaser that peaks 200mw, and by just seeing the beams you can't tell the difference.
 

TheDukeAnumber1

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I agree, there is some merit to ballparking a lasers power, especially if you have plenty of comparison I.E. lot of lasers or metered lasers, and studying known outputs compared to current draw. When you look at the potential % off though it can be quite high.

Kinda how Cyparagon pointed out, the people who would have a good guess at it will usually have an LPM anyways.
 
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I must be really pretty or something...To see such a wonderful, informative, and well thought out thread by Daguin be dismissed by folks who want to make arguments based on flawed an subjective data.

Perhaps, it would have gotten through better to the noobs, if Dave had focused the topic towards folks who want to sell lasers and want true accuracy.

Clearly, noobs are going to think they know better...apply "logic" they think we haven't considered yet, etc...With some folks, there's just no convincing, and :horse: is more effective. It reminds me of freshmen university students who are sure they have an insight over their teachers because they took a summer workshop.
 
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Belch85

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My point exactly scumbagathiest, perhaps the original post was not written for the benefit of all audiences.

I see I have come about this the wrong way :yabbem:. I thank you for your patience with my incessant pestering; I hope to grow in this hobby and one day add to this thread. I'd like to add some useful information (in addition to what Dave has already posted) that will clearly explain some basic principals that can give clues to the power output, and some basic principles that insist/require an accurate measure.

In other words - useful information for those without an LPM (which is what the title of this thread implies). If I don't have an LPM - I'd like to know a little more than "You need an LPM".

Thanks for your original post Daguin - I'm doing my research and learning every chance I get. I know I should read my text books more - but sometimes I really enjoy a good conversation; especially when I can learn from a willing expert. Thanks to all the guys on here who posted constructive comments regarding my questions. :thanks:

Why can't we all just be friends? :friend:
 

lasersbee

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My point exactly scumbagathiest, perhaps the original post was not written for the benefit of all audiences.

I see I have come about this the wrong way :yabbem:. I thank you for your patience with my incessant pestering; I hope to grow in this hobby and one day add to this thread. I'd like to add some useful information (in addition to what Dave has already posted) that will clearly explain some basic principals that can give clues to the power output, and some basic principles that insist/require an accurate measure.

In other words - useful information for those without an LPM (which is what the title of this thread implies). If I don't have an LPM - I'd like to know a little more than "You need an LPM".

Thanks for your original post Daguin - I'm doing my research and learning every chance I get. I know I should read my text books more - but sometimes I really enjoy a good conversation; especially when I can learn from a willing expert. Thanks to all the guys on here who posted constructive comments regarding my questions. :thanks:

Why can't we all just be friends? :friend:
Perhaps YOU could accumulate the data required to make
a chart of how to test Lasers without an LPM to fill your
Grey Area...

I could see that you would no doubt need (to keep data as
accurate as possible) to purchase at least 10 of each type
of Laser powers on your chart in each of the Laser Wavelengths
on your chart.

Then find a common non LPM testing method that anyone
can do and has materials with identical properties around
the house (to keep costs low).
Then you could post that compiled chart on the Forum for
members to duplicate your results at their homes.

Or for less $$$ and time you can buy a Laser Power Meter
and get much more accurate results... Or even have a
member with an LPM measure your Laser for you.

The choice is ultimately yours...:beer:


Jerry
 

Gun

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Perhaps YOU could accumulate the data required to make
a chart of how to test Lasers without an LPM to fill your
Grey Area...

I could see that you would no doubt need (to keep data as
accurate as possible) to purchase at least 10 of each type
of Laser powers on your chart in each of the Laser Wavelengths
on your chart.

Then find a common non LPM testing method that anyone
can do and has materials with identical properties around
the house (to keep costs low).
Then you could post that compiled chart on the Forum for
members to duplicate your results at their homes.

Or for less $$$ and time you can buy a Laser Power Meter
and get much more accurate results... Or even have a
member with an LPM measure your Laser for you.

The choice is ultimately yours...:beer:


Jerry
*cough* Buy a Laserbee LPM *cough*
 
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hakzaw1

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IMHO buying a good LPM is never wasted $$.
most can be later sold with small depreciation.
New LPMs are coming with better prices.

But as many have said- there are no truly good substitutions for a good meter.

You do have some options however- connect with a member locally who owns a meter- it has been a tradition at laser forums to meter lasers for others at no charge.
I have been shipped lasers to meter by those with no meter. They cover the return postage and then know what their lasers are outputting.

If you take a look at my avatar you will see two 635 red lasers-- one is 200mW the other is 400mW- can you tell which is whicH?
is the 400 twice as 'bright'?-- the green is a 500mw ( OSpec to 700mW) and the blue is a 445nm 1W--

FYI if using your eyes to judge brightness you would need an 800mW 635 to look twice as 'bright' as my 200mW- the factor is not 2 its 4.
so get a LPM- easy to sell later- and a good item to own.
 
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LaserCo

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Hey !
you are great! how do you find time for all of this???
:)
+ Rep to U too

:crackup: Why MUST there be grey area? :crackup:
Why, in the world, would you believe that your "intuition" is more capable of discerning truth than our empirical testing and academic history?

You have not "brained your damage."
You are simply a human who's mommy and grammy lied to you
You are NOT the smartest child in the world
You aren't the prettiest or most handsome child in the world
You are just a human

Humans like to *think* that they can think things through and come up with the right answer
Unfortunately, that is not valid

You have read through this thread and admitted that we know more than you about the subject
Then you ask, "Are you sure?"

Let me answer that as succinctly as I can
Yes. We are sure

If there were another way, we most assuredly would be crowing about it
LPM's are expensive
Professional LPM's are SIGNIFICANTLY more costly than any of the REALLY CHEAP "hobbyists" LPM's offered
If you think that a Laserbee 5W costs more than you want to spend, try pricing out a Scientech S310 or H410 ;)
NO ONE here *wants* to spend money on an LPM

Unfortunately for the hobby:
Retailers, especially the Chinese "mega retailers", are as willing to lie to you as your mommy and grammy are

If you read through this thread (instead of just jumping to the end to write your response to the title of the thread like most Noob's do), you will have seen my post showing me lighting a match, instantly, with a 32mW laser.

Should we then surmise that all (or most) 35mW lasers can light a match instantly?

Even knowing what the current being produced is and which diode is in the laser, will only give us a **WIDE** range of potential outputs
If knowing that your laser is somewhere between 1.2W and 2.2W is enough for you (there is your only real potential "grey area"), then it doesn't really matter, does it?

If, however, you wish to have a reasonably close idea of what your laser is putting out, we *ALL* are left with this . . . . .

There is ONLY ONE WAY TO KNOW what the output on a particular laser is
You MUST measure it with a Laser Power Meter

Peace,
dave
 
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weirdmeister

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what about testing like ballistics gel?



take a worldwide available candle (wax) with a special colour eg brown (mass coloured-not surface), slice 2cm piece
and lay it on a light (neon or led-should be cold) to see trough a bit...shine on 30seconds with your lp from above and measure the depht and the diameter of the fresh molten pond and multiply them
depht will be more when focused,diameter will be more with non focus lp

what you think ?
 




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