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Radim's laser painting

CurtisOliver

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Look who's just resurrected. :p
Long time no see. Glad to see you back on and ok Radim. :beer:
 

Radim

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Good to see you too, Oliver. :yh: I'm just curious what will be the reactions here...
 

CurtisOliver

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They may go a bit pale, as they will have just seen an internet ghost. :p
 

Radim

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Definitely. :D But more curious I'm about the pic I posted. To be honest I'm not sure to think about that.
 

CurtisOliver

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What image host are you using? As it is possible i'm not seeing it due to blocks at work.
 

Radim

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Ah... It's my temporal webhosting now. Maybe this is the reason. Ok, than you'll see it home. :)
 

CurtisOliver

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Ah... It's my temporal webhosting now. Maybe this is the reason. Ok, than you'll see it home. :)
Yes it is. I just checked the URL's listed in your post at they are blocked for me. I'll have to check them out when I get home. :)
 

paul1598419

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Glad to see you back, Radim. I have been wondering what happened to you. I can't look at your image either, but may know what you are talking about. It isn't a hologram, but might be an image that can be seen in a picture when you focus your eyes past it. I forget the correct terminology for this but it has been done for years by others. I have known about it for over 30 years now. I am currently out of rep, but will get you when I have more.
 
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Encap

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Hey Radim nice see you have returned to LPF ---nice post---no trouble seeing the pictures here with Foxfire on laptop. +rep

Looking forward to seeing some new laser painting.

Whatever became of the Optotronics RPL II 532nm 1400mW? Have you found it to be useful tool for laser painting yer?
 

Radim

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Re: Radim's Laserpainting Art & more

The Hologram Question


Glad to see you back, Radim. I have been wondering what happened to you. I can't look at your image either, but may know what you are talking about. It isn't a hologram, but might be an image that can be seen in a picture when you focus your eyes past it. I forget the correct terminology for this but it has been done for years by others. I have known about it for over 30 years now. I am currently out of rep, but will get you when I have more.
Thanks Paul, your scepticism is very welcome. Since I'm also sceptic in this case, that's why I ask here. And I do not think it is stereogram - that you probably mean. For example like this gorilla scratching its head. I've seen tons of them, they are pretty hard to see, but more important - you can print it and use it, here the printing won't work - see below in facts why. To be honest I did not even find something like this in my book of optical ilusions (yes, I'm curious about them, I like to analyze them and I use them).


Hey Radim nice see you have returned to LPF ---nice post---no trouble seeing the pictures here with Foxfire on laptop. +rep

Looking forward to seeing some new laser painting.

Whatever became of the Optotronics RPL II 532nm 1400mW? Have you found it to be useful tool for laser painting yer?
Thank you, Encap. Do you see some kind of hole, colour change when looking in different angles?

Regarding the Beast - I did some laserpainting with it, but I need to do more. On one hand to have more pics for review, on the other to have more experience with the laser. If I sumarize it shortly. I would not recommend such a laser for anyone just to have something cool or to use often (than there are Jet Lasers awesome instead). This is laser for special purposes only (no doubt), it is dangerous extremely, if not handled with care, heats up a lot, drain batts fast etc. On the other hand, I would recommend it to those who can have some specific purpose the laser could fit - for example myself - high quality beam of high power for large and distant areas illumination on laserpaintings. Power without quality gives you enough light, but thick or deformed beams in distance (not wanted). For most specific purposes indoors lab lasers are more suitable (better cooling), I guess.

Still I needed to take extra care, since even if diffraction grating is used, the side beams (higher orders maxima) are significant eye danger due to high quality beam (divergence, diameter) and power. I was quite worried, I would do something wrong during that laserpainting, so I have special rules just for this laser use: Locked and stored till before use - usually I have lasers ready on their spots on scene and activated, battery out and kept warm since it drains a lot and internal resistance rises with lower temperature. Also I use glasses during almost all time. (Note for those not aware of my laserpainting procedures: Wear proper laser safety eyewear always when using laser.) If I could say my impressions from the forest - it is something from the other world. It flooded entire area with bright green light, I bet the glare was visible quite far even through trees.


The "Hologram"?


For more convenience for others I posted the pic here again. Original post is here.



Detail taken as from instant laserpainting artwork - Two Souls meeting in Prague (not published)
BTW: It is just screenshot from mobile beyond original artwork pixel resolution (= continuous transitions from individual pixels in captured area were calculated by "zoom" algorithm of the QuickPic image gallery app) - the suspected hologram is in the QuickPic widow



Let's sumarize some facts:

  1. Facts about the exposure:
    Laser - the key factor for holograms spatial, but mainly temporal coherence. I've calculated the temporal coherence length for my SKY Lasers 532 nm 800 mW rated. If I remember well it was 2-3 mm according to data sheet inputs I used. The WL Evo used in this laserpainting was on in full power and TEM00. It was running for about hour before on lower power, so it was quite warm. Before the exposure I put it on full power and had it on for a few minutes. However WL Evo has on first look much more beam quality compared to SKY Lasers. I posted here long time ago various dot shots of interesting mode hopping under special conditions. But here it run very stable, nice and sharp TEM00, no mode hopping.

    Optical setup - there was an optical setup similar to holograms, but just because I wanted to create the artwork just reminding it a bit. I did not suppose to get this "hologram" even I was aware about the hypothesis (meaning method how to create digital holograms of large objects + some stuff from complex system behaviour) already and I wanted to do experiment later when I would have more time for that - but it was just fun rather than experiment.

    Camera and exposure - Canon EOS M100, resolution 6000×4000, aperture f/4, exposure time 1/13 s, ISO 6400, focal length 35 mm - was held in hand (key factor against the hypothesis of this being hologram - stability issue). On the other side there is very short exposure time compared to like 10 s in normal plate/film holography.

    For holograms there are no lens used to transform the image, but here we have lens (large hologram cannot be expected). However there might be used lens to transform the waveforms to capture interference patterns on CCD - like in microscopy holography.

    Check this setup for reference (source: Wiki - click on pic for more details):




    There were certain laserpainting techiques including the new one used, but I'll not mention them to keep on facts and not to lead the discussion into speculation. In adition, I'm planing to develop the techiques to create more artworks like this.



  2. Facts about the picture (suspected to be a hologram) and how I discovered it in the original artwork:

    When I was exploring the artwork I noticed some kind of like 2D space distortion, what I thought was perspective illusion. But as soon as I noticed the colour changed depending on the angle of view in some small area I got question, why is it happening there and not on the rest of the pic? My mobile phone I viewed it on is Samsung S6 with OLED display.

    I examined this anomaly and selected the place where the "2D -> 3D -> 2D" distortion appeared to be the strongest and took a screenshot of it. The color change was evident, depending on angle of view. I have not seen it before on my mobile as it reminded me some old LCDs where it was common, but my mobile has quite a high quality screen not having this issue to be noticed. Damn it, there is some interference stuff happening in the display itself!

    Short note about displays:

    As you probably know - displays composed of pixels are esentialy diffraction gratings - I did many experiments with laser pointer to see the inteference patterns from display reflected light. In adition, they are usually 2 layers of glass or something and the display is between them, entire setup is quite thin and that was one of the reasons why interference occured on older displays. This setup is however used even in modern displays, but some features are added to cancel the interference.

    Check here for more:
    https://en.wikipedia.org/wiki/OLED
    https://en.wikipedia.org/wiki/Liquid-crystal_display


    When I accidentaly switched to task manager, I noticed shalow (1-3 mm approx. - might be more if the pic is larger on computer for example) hole in my screen! So, I took a screenshot of it and you can see above.

    I sent it to my friend and his son found people (me and my sister taking the pic of us) there. The fact is I saw it once I focussed more precisely into these 1 to 3 mm 3D space, where the wierd stuff is happening. The entire scene has depth only of 1-3 mm (so it is quite hard to refocus), but it is 3D there. I even observed typical features of holograms (colour change, 3D appearance).

    The most important fact is, the angle of the view on "hologram" is totally out of optical setup - like the camera was somewhere else. The "hologram" is just a little fraction of original image, but I could recognize us exactly as we stood when we took the picture - just the angle of view was odd. There is too much coincidences to say it is just random glare. Especially as I can see even her eyes and even pupils.

Further I would like not to use my hypothesis, which is to be confirmed, as the fact. According to this hypothesis this setup could create such kind of the hologram - I went through it quite deeply and found it could be plausible. Here I'm interested about your opinions before me and my friend initiate that science guy to take a closer look on it.



If this really is hologram, than you may look forward for more description how I got it (after I create proper working aparatus prototype - may take a while).

As I mentioned already, due to the used techniques (with some of them very special) the synergy of them could plausibly create hologram (this is the hypothesis to be confirmed). But I did not intended to get this now, since I wanted to do it more precisely later and it was just first attempt of this techique to do the artwork and potentially get some preliminary results.

Thanks for any comments and opinions in advance.





Update on the "Hologram" question: Where is the aditional information stored?


(For higher resolution click on the image.)


Here you can see why I'm so insanely curious about this strange green square. In holograms, the information about 3D space is stored in the speckles (rather than "wavy" pattern as shown on pic below).




Source: Wiki - click on pic for more.

The hypothesis is:

That display (OLED is the best I found so far, that's why I use my mobile to explore interference patterns of my artworks) is able to cause interference in "unwanted" color change when viewing under various angles. Here this little imperfection of display technology is used to get the information hidden/coded in the speckle/noise of the photograph.

Camera sensor:
Type: CMOS APS-C
Size: 22,3 × 14,9 mm
Resolution: 6000 × 4000 px

As you can see in original image detail - there are just a few pixels from full 24,2 Mpx available. Here at these dimensions some holographic effects based on phase difference of 532 nm could happen IMO.


What do you think?


 
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paul1598419

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Still have a large square blocking the center of your photo and, now, avatar. It says "QuickPic" at the top left. If I could see what you are talking about, I might know what is causing it. BTW, + Rep. FINALLY!
 
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Radim

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Still have a large square blocking the center of your photo and, now, avatar. It says "QuickPic" at the top left. If I could see what you are talking about, I might know what is causing it. BTW, + Rep. FINALLY!
It is just background wallpaper in my mobile (earlier artwork), do not pay attention to it. It was much easier to see the depth with some frame, so I left it as I observed it first time (in task manager). The image is the green square itself. It is better to see it from distance and side a little bit - in dim room (light reflected makes it harder).

Thanks, I have spreading limit applied on you. Strange after such a time. Seems I need to spread some.

Edit: Also it is better to look away, focus somewhere else in the room and than go back to the screen and it should appear as the green square is below. If you focus in between the square and frame, the 3D scene is there. Still it is very shallow and 3D is somehow "flat".
 
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paul1598419

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I have tried, but still can't see it. The 3D image sounds like what I think was called the third eye. Many pictures were made like this and if you focused your eyes past the picture, the 3D image would come out of the picture. It works similar to a stereo scope, but you don't need the scope and the image is hidden in the picture until your eyes catch it just right.
 

ArcticDude

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It is just background wallpaper in my mobile (earlier artwork), do not pay attention to it. It was much easier to see the depth with some frame, so I left it as I observed it first time (in task manager). The image is the green square itself. It is better to see it from distance and side a little bit - in dim room (light reflected makes it harder).

Thanks, I have spreading limit applied on you. Strange after such a time. Seems I need to spread some.

Edit: Also it is better to look away, focus somewhere else in the room and than go back to the screen and it should appear as the green square is below. If you focus in between the square and frame, the 3D scene is there. Still it is very shallow and 3D is somehow "flat".
Hey, Welcome back my Friend!! :wave:

I'm glad to see you back in here!! :beer:
 

Radim

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Yes, I think you talk about the stereograms, not sure about third eye. This is however something else, I do not need to focus beyond to see the hole. And from colour change depending on angle, I assume there is some interference happening in screen itself. Maybe it is issue with your screen - on some it appears better, what I've observed. Anyway thanks a lot, let's see what others will see.

Edit: Also it helps to make it smaller on screen (shift + mouse scroll), maybe the pixels do not match.
 
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Radim

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Hey, Welcome back my Friend!! :wave:

I'm glad to see you back in here!! :beer:
Hey, ArcticDude, thanks a lot. I'm happy to see you too. :wave: I was too busy with work, sorry for not being here so long.
 




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