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Newbie: Learn before I can burn

paul1598419

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Taken from the batteriesplus website - "The specs are nearly identical, though the new green 25R batteries have a lower internal resistance, and a longer life cycle"

So a lower internal resistance is good for non intensive devices?
The dynamic internal resistance of a battery is analogous to the ESR, or the effective series resistance of a capacitor. Both are desirable properties of both batteries and capacitors. The high discharge batteries must give up some of that property to gain the high discharge current needed for some devices.

Kermit, for $100 you could start off with this laser. 593.5 is a nice color! :crackup:

http://www.cnilaser.com/PDF/MGL-III-593.5.pdf

-Alex
Yeah, right, Alex. In your dreams that laser is $100.00. I didn't see what they are asking for it but wouldn't be surprised to find it in the 10s of K$.
 

Hap

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The dynamic internal resistance of a battery is analogous to the ESR, or the effective series resistance of a capacitor. Both are desirable properties of both batteries and capacitors. The high discharge batteries must give up some of that property to gain the high discharge current needed for some devices.



Yeah, right, Alex. In your dreams that laser is $100.00. I didn't see what they are asking for it but wouldn't be surprised to find it in the 10s of K$.
Actually Paul, DL has a 10mW model for only $1400 :eek:

-Alex
 

Kermit101

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Hap, i think the beam divergence on that laser you recommended may be too high. (1.5mRad?).

I'm unsure if the beam will be good for star pointing, as after a few Km it may have expanded too much. :undecided:
 

Hap

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Hap, i think the beam divergence on that laser you recommended may be too high. (1.5mRad?).

I'm unsure if the beam will be good for star pointing, as after a few Km it may have expanded too much. :undecided:
Kermit, I was only kidding with that laser. This kind of laser isn't made for star pointing at all, only for scientific research etc... :beer:

-Alex
 

Radim

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Hap, i think the beam divergence on that laser you recommended may be too high. (1.5mRad?).

I'm unsure if the beam will be good for star pointing, as after a few Km it may have expanded too much. :undecided:
1.5 mrad is not that bad. High powered blue diodes might have even 5 mrad and more. These look a bit like flashlight when pointed on sky. If you have 1.5 mrad pointer, due to perspective you will perceive it as straight line when pointing on sky. Still the beam will look like "light saber blade" a bit as it won't scatter that good in higher layers of atmosphere (less air density, less dust and stuff there). It seems like the beam ends in few hundred meters, but do not be fooled with that. It travels further untill it hits something. No end.

Here is a pic from review of my 473 nm laser:



It is about 1 mm beam diameter at output and 1 mrad divergence. It might seem a bit blurry at the end of the beam, but you will see it as straight line. Important on this pic is the end of the beam which you see, but in deed it does not exist and the beam continues further. Be aware of that, as you might accidentaly hit an aircraft, when thinking it ends somewhere. Some teenager got into problems because not being aware of that.

If you consider star pointing purposes, or shining it on sky. Be extremely careful, as planes might not be seen or appear as star. Because of this even if you are sure it is a star, do not point on it directly, instead circle around it. It is a good habit to adopt and stay safe. Also your audience will see it and you can teach them this easy safety procedure. Might seem obvious, but untill said to do so, people often won't realize that. :)

Edit:
There are a lot of loyal fans of certain companies that sell laser pointers here. They defend them like they were family. I find it kind of funny.
Not me, even I like them, I do not count myself to the set of "defenders unless dead" fans. I do not count myself even to the oposite set of "haters unless dead", which is also kind of funny as well. I focus on my actual experience and comparsion with peers I did business with and further references I consider as reliable. I have no reason to accept any given dogma. As Adam Savage from Mythbusters says: "I reject your reality and substitute my own." In the sense of Mythbusters of course - so tested only. :D :beer:
 
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diachi

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Hap, i think the beam divergence on that laser you recommended may be too high. (1.5mRad?).

I'm unsure if the beam will be good for star pointing, as after a few Km it may have expanded too much. :undecided:

1.5mRad is fine for start pointing, you don't really need the best divergence for that. Never hurts mind you. The beam would just look like a thin line extending into the sky at 1.5mRad, very hard if not impossible to notice any divergence in that case.

Looks like Radim gave you a fairly detailed answer. :)
 

Kermit101

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Wow, ok that seems fine then. I'll be sure not to point at anything that is moving or flashing (it could be an aircraft), and also not to point directly at objects in the sky but rather circle them as radim said.

Thank you for the help once again, without you experts i wouldn't have known left from right.
 

CE5

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Hello Kermit101, and welcome! :wave:
As a student you are in a unique position moreso than many others, you can still decide what you are going to do in your life. Some, like myself decided decades ago what we were going to do. I had an opportunity and an interest to pursue lasers as a young lad, but at that time computers were the next big thing, so off I went in that direction. Although as time progressed, lasers did find their way into computers, and there too they made a huge impact. And lasers continue to make a tremendous impact on various facets of our technology and daily lives. We have advanced so far in such a relatively short time period, from the early ruby and gas lasers to now- even developing nanolasers for on chip optical computing!

With there being so many choices it then becomes a question of where do you feel your main interests lay. Perhaps one of the ways to put this kettle on the boil, would be for you to explore several of the current laser, photonic & optical trade publications. I will list several below but before I do, I would once again like to welcome you here because even for old dogs like myself I find this a superb laid back place in which to learn about lasers, and I have in fact learned a great deal in such a brief time span. Since like yourself, I am also a new student here and after delving headlong into the world of lasers, I am still conflicted about my decision all those years ago. If I would have known back then just how flat out cool lasers were to become, I probably would've had an even tougher choice to make. At the very least I would have put forth a greater effort to keep more apace with the goings on in the world of lasers.

One of the main reasons why I'm recommending a few of these trade publications to you is because as a fellow new student, they have been very helpful to me. In just the first one, the superabundance of laser applications are self evident. You have expressed an interest in lasers, this places you on a very promising and £ rewarding path if you choose to pursue it. Hopefully you will find something within these links to help you along the way. Without further ado-

http://www.laserfocusworld.com/index.html

OPTICS JOURNAL

Laser-Community

https://www.photonics.com/

https://spie.org/about-spie/about-the-society/spie-europe

Sure wish I had stuff like this at my beck and call when I was a lad. :drool: :whistle:
 
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Kermit101

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Wow, thank you CE5 that was epic. I understand what you mean when you say that i have a whole world of topics i can delve into, I'll certainly dip my toes in all the puddles as it were.

Lasers are a VERY cool and interesting subject for me, it's harder to find anything more awesome than a beam of radiation.... (i mean cmon)

I think that I'm going to go into biochemistry as a future career, I'm going to enrol in a university course in BC when i get my A-Levels *fingers crossed*.

The passion that i have for lasers will always remain in me though don't worry. Hopefully i will be able to use laser in the laboratory for chemical spectrometry or something like that.

I will purchase my own more powerful laser parts and build "expensive but worth" it rigs.

Once again, big old thank you to everyone who helped me on the forum, paul, radim, bob.... (sorry, I've forgotten some names). Lots more learning and burning to be done!

:D
 

CE5

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Cool breeze. :)
In that Laserfocusworld link, towards the bottom of the cover page there are other links to related pubs that they offer. Laserfocusworld, is really such a great portal.
Here is another one from Laserfocusworld, that is a bit more specific towards your interests.

http://www.bioopticsworld.com/index.html

And since there was some discussion about Holograms, and the emerging applications that they hold. Here is a cool short video clip, with a Biocentric focus. The applications for this sort of interactive*holography, will also be adapted and developed to assist more directly with Biochemistry research as well.
It's a pretty exciting time for folks that have an interest in becoming 'Lightworkers'. The future's so bright, ya' gotta wear shades. :cool:

 

paul1598419

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That was interesting. But, I think there are using the term hologram very loosely here. These aren't real holograms in the sense of the word, but reconstructed images that are digital in nature and, since light can't appear in thin air it is most likely an optical illusion similar to the coin floating in midair device that most of us have seen before. I would like to know more about how they are projecting this and how accurate to the actual heart it is. I doubt it has anything to do with lasers too. I subscribe to Laser Focus World and have for several years. There is good information to be had there, but you have to sift through the continuous ads for different products.
 

CE5

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Well I suppose you can inquire with RealView Imaging - Interactive Live Holography
"Since light can't appear in thin air' :thinking:

I also feel they are using the term 'holograph' in the truest sense and definition of the term =
"Originating from Prof. Gabor's Nobel-prize-winning invention, holography is the best method known to science to precisely reconstruct and display 3D objects in free space. As holography is an optical reality and not an optical illusion, it is almost impossible to distinguish between a high-quality reconstructed hologram and the original real object.

Prof. Dennis Gabor (Nobel Prize Laureate, 1971), Inventor of Holography
hol·o·gram

/häl, gram,hōle, gram/ noun a three-dimensional image formed by the interference of light beams from a laser or other coherent light source. a photograph of an interference pattern that, when suitably illuminated, produces a three-dimensional image."

From what I gathered @ their website, Digital Light Shaping? technology this tech has everything to do with lasers.

And it was very clearly explained that the heart used in the demo, was displaying a true image of the patients actual organ. That can be manipulated in various ways.

Welcome to the future that is now.
 

paul1598419

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Dennis Gabor was trying to use light imagery to make a whole image on a photographic plate to be reconstructed with electron microscopy to try to get optical images of atomic sized structures. That was in 1947, long before the laser was to come. He managed to make a crude very flat hologram using the Na line of light and tried to polarize it as best he could. All holograms consist of photographic film emulsions exposed to two laser beams and developed into a static image. There have been 3D imagery done with holography and movie film as early as 1973, but these are only the illusion of 3D. So, unless it conforms to Dr. Gabor's technique, it isn't a hologram in the strict sense of the word. I have been making holograms myself since the early 1980s. If you think about the imagery that these people are passing off as true images of the heart in real time, it seems unlikely as there is no way to do this as explained.
 
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CE5

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For the sake of brevity I'll use the following clips as examples =


And also from as far back as 2011, the following clip talks about interaction with 'Plasma'.


Now since the RealView, tech appears to be using a semi? parabolic reflector- would that not focus and place the image over the table of the device allowing for interaction? And it also appears as if the RealView, display device is will/also be located within a specially designed room/space and would or could that also not achieve the effect of placing the viewer 'within' the hologram and thereby allow interaction with it? I'm interested in this debate, since I've not worked directly with holograms in the creation and implementation of the hardware other than to don a pair of VR, goggles to interact with the current widely available Low Tech, soon to be obsolete and replaced VR.

Now the following clip(s) are to illustrate the use of a rotating platter. Since it appears as if the RealView, tech also employs some sort of platter? (with the raised puck in the center) Volumetrics?


And perhaps to a similar? extant =


https://voxon.co/

Now obviously the platter in the USC, clip has a hard mirror mounted on it and is spinning it to achieve the optical effect. Although it does not* appear as if the RealView, tech has any hard reflector mounted on the platter/platform?

And lets talk about the use of ultrasonics (Volumetric Haptic) now as well =



Now is it possible that RealView, is using a fusion of these technologies?

Because it appears as if RealView, has developed the technology to crack this nut wide open.


I would hazard a guess that RealView, is employing Ultrasonics (Volumetric Haptic) technologies in a spinning platter type config to help achieve their proprietary interactive imaging effect.

Much of what I've presented above was occurring in real time, so I imagine that a real time view of the heart, or any other organ being imaged via an MRI, CTscan, ultrasound etc; device and can then be fed to the input of the RealView projector, to render the interactive 3D image in real time as well.
 




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