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ArcticMyst Security by Avery
Possible range wit focus
- Thread starter nc9210
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Arayan
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can you give us more details?
I always thought laser beams would be completely parallel; but obviously this is not true. My laser pointer does have a point after 10 meters with 15mm diameter. After 100 meters this is already 15cm!
I just like to know whether it's possible to held the beam constant at a considerable distance and like to test this eventually...
I just like to know whether it's possible to held the beam constant at a considerable distance and like to test this eventually...
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Yes... you will need a Beam Expander to enlarge the beam first and then
it can be focused down at a distance..
Jerry
it can be focused down at a distance..
Jerry
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Post counts. :beer:
cmak
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First off, spamming-to-boost-post-count is not ma thing and I deleted my earlier post to confirm this
Second, to be more specific, what I meant to say is that I enjoy threads posted by new members as their first (or one of their first) threads that are either nonsensical (not the case here), too vague (bingo), or can be answered fairly easily by incorporating the usage of the spectacular search function!
Laserbee's post (#4) should answer the OP's question. :beer:
peace & thanks
-cmak
Second, to be more specific, what I meant to say is that I enjoy threads posted by new members as their first (or one of their first) threads that are either nonsensical (not the case here), too vague (bingo), or can be answered fairly easily by incorporating the usage of the spectacular search function!
Laserbee's post (#4) should answer the OP's question. :beer:
peace & thanks
-cmak
@cmak
@all
In the last hour's i played a liite bit with my laser pointer and 2 magnifiers. Afaik the pointer uses a beam expander. With the 2 magnifiers i made a point from ca. 5mm in the distance of 10m, but he point was really dark and much light is around this point. Is this a queston of coating? If i do the same for a long distance, is this possible or is the point as dark as the light arround?
regards
Nicole
thx
why? i read nearly all threads from the last 12 months in this forum and learned a lot, but nowhere i found a post about long distance.
Are you really sure? To expand the beam is one part, but the expanded beam continues divergating. To focus the expanded beam i need a lens with focal length of 100m? I'm realy sure this one does not exist.
@all
In the last hour's i played a liite bit with my laser pointer and 2 magnifiers. Afaik the pointer uses a beam expander. With the 2 magnifiers i made a point from ca. 5mm in the distance of 10m, but he point was really dark and much light is around this point. Is this a queston of coating? If i do the same for a long distance, is this possible or is the point as dark as the light arround?
regards
Nicole
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Well... if you are so sure...
why are you asking us Noobs who never read anything here on the Forum or even
experimented with Lasers....:thinking:
Jerry
Arayan
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@lasersbee
Do you know a lens with a very high focal length?
@Arayan
Thank you for showing me the difference. If i expand the beam first and then focus for a long distance it will reduce uniformly and divergate again behind the focus. Ist this right? This looks like my experiment with the 2 magnifiers. But in my experiment i loose many light :-(
@steve001 WOW!
I have never seen anything like that. Do you know more about the used equipment? It seems to be a teleskope? Is it moified in any way? And what kind of laser is used? This looks like a fiber-bound type with any type of optic attached?
regards
Nicole
Do you know a lens with a very high focal length?
@Arayan
Thank you for showing me the difference. If i expand the beam first and then focus for a long distance it will reduce uniformly and divergate again behind the focus. Ist this right? This looks like my experiment with the 2 magnifiers. But in my experiment i loose many light :-(
@steve001 WOW!
I have never seen anything like that. Do you know more about the used equipment? It seems to be a teleskope? Is it moified in any way? And what kind of laser is used? This looks like a fiber-bound type with any type of optic attached?
regards
Nicole
Last edited:
Asherz
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A BEAM EXPANDER! Which is exactly what Laserbee said to use.
jesus.
And wtf? Fiber-bound? uh?
The black 1,2m long part is a beam expander??? Sorry, i have never seen a device in this size. Or do you mean the optics mounted on the laser? This, of course may bee. :banghead:
What do you mean with wtf? And whats the problem with Fiber-bound lasers?
Grix
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The long black part is a beam expander, yes. But you are also right: A telescope would actually work as a beam expander too.
Arayan
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Yes, the beam expander is essentially a telescope with high-quality lenses and also specific to the wavelength of the laser used.
