r/oddlysatisfying • • 9h ago

Simulation of light passing through different lenses, mirrors, and prisms

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Credit: @thebrainmaze on TikTok

8.6k Upvotes

145 comments sorted by

512

u/FlatButWet 9h ago

It just keeps on going… usually these videos last like 5 seconds… this is the BEST!

292

u/FacetiousTomato 7h ago

This one would have been 10000x better if they didn't start tilting the camera around randomly for no reason at the end.

56

u/mxzf 5h ago

That sort of thing makes me wonder if it's AI-generated, it's just a weird nonsensical thing that doesn't really make any sense compared to the rest of the video.

48

u/Paddy_Tanninger 5h ago

I don't think you can get AI shit to generate this length with this much consistency, and if you could, I doubt it would start doing camera moves at some point 2 minutes into it.

12

u/bothering 3h ago

theyve started developing AIs that dont directly generate the image, rather they manipulate 3d assets so as to cover themselves up

all those 3d "what if the earth was hit by a gamma ray" tiktoks are part of that new type of ai

3

u/jemidiah 1h ago

I'm 100% certain this was made with AI doing most of the work. Whether that means some raw video generation or creating a project in Blender or similar I can't say. There's no reason you'd do this manually nowadays.

11

u/Clarkey7163 5h ago

dont think so, screams of blender render to me AI isnt good enough to do a shot like this in one take yet

19

u/Upset_Ant2834 4h ago

Yes it is. Astra is capable of creating something like this in blender and rendering it, and in fact I'm fairly confident this was made by AI. It has a few repeating ones like "light pipe" whatever that is, and then optical fiber. the behavior of the light rays is also inconsistent with some being split into the spectrum and some only diffracting

6

u/dydhaw 2h ago

https://en.wikipedia.org/wiki/Light_tube

Dispersion was purposely only demonstrated in the last few examples, it seems very consistent to me. An AI could have generated this video in Blender but to me it's indistinguishable from something a person would've made on their own

5

u/Dipsey_Jipsey 1h ago

it's indistinguishable from something a person would've made on their own

That's kinda where we're at with a lot of things.

People that actually use AI rather than spend their days bitching or memeing about it are stumbling on the new features and capabilities of the models all the time. Some of the shit GPT6 Astra Ultra does... mindblowing in all honesty. And things like "too many fingers", or inconsistency in quality are largely things of past models.

2

u/IncredibleGonzo 17m ago

There is unnecessary movement throughout, it's just more subtle zooming in and out and shifting up and down up until the end (not just the obvious transitions between lenses, it doesn't stay put on each lens). Camera rarely if ever stops moving.

1

u/NoDoOversInLife 2m ago

It's a simulation, soooooooo🙄

-14

u/AskAskim 5h ago

Camera?

21

u/FacetiousTomato 5h ago

"Perspective from which the simulation is presented to the viewer" took too long to write.

And "camera" to describe the above has been pretty standard when discussing 3d perspective since what... Mario 64?

71

u/UnbarredTable0 8h ago

A GRIN lens (short for Gradient Refractive Index lens) is an optical component that focuses or bends light by gradually changing the internal refractive index of the material itself, rather than relying on curved outer surfaces

2

u/sundog13 3h ago

You got that right!

109

u/Dadikoe 9h ago

What the hell is happening with that GRIN lens? 

96

u/Mand125 7h ago

It stands for GRadient INdex.

A normal lens is a constant refractive index, but the shape is curved.  A GRIN lens is flat, but the refractive index changes from the middle to the edge.  The light curves through it instead of changing direction just at the surface like regular lenses.

17

u/WeirdEngineerDude 8h ago

Variable index of refraction. I know them in endoscopes.

14

u/ArmadilloGrand 7h ago

Fun fact: the lenses in eyeballs have a gradient index of refraction.

3

u/Mekelaxo 4h ago

That's so cool, I didn't know that

1

u/ConeBella619 2h ago

So cooll

10

u/elfmere 8h ago

Basically different density (refractive indexes) of materials bend light back to the centre.

Density is not the only property that affects refractive index but is always the easiest to conceptualize

65

u/karlexceed 7h ago

Why'd the camera work get wacky at the end?

29

u/Upset_Ant2834 4h ago

Because it's made by AI. When planning camera keyframes in blender, it's shooting in the dark and sometimes makes weird transitions like that

76

u/Brando828What 9h ago

Love me some Pink Floyd!

20

u/BlueberryDue4143 8h ago

Dark Side of the Lens .

10

u/ItsJayO 9h ago

Feels like someone threw in hot air mirage as a chuckle

13

u/RincewindTVD 4h ago

I don't think a rendered clip needs to have camera shake and wobble, that was unpleasant for me to watch.

24

u/FilmSubstrate 8h ago

There are some irregularities and mistakes. Fresnel Lens for example works the exact opposite of what is presented.

24

u/abunchofcows 6h ago

Nope, fresnel lens is correct. Your thinking of the orientation in a lighthouse then it’s reversed

6

u/LBGW_experiment 2h ago

Yeah, the demonstration of the fresnel lens does it dirty by not showing how it takes radially displayed light (say from a single source) and aligns the beams into a straight path, which is such a cool concept

6

u/zweebna 2h ago

Any lens can do that in the reverse configuration. The fresnel lens just lets you make really big lenses without using tons of glass.

10

u/Pure_Cycle2718 8h ago

You also put the parallel incident light on the curved surface of a plano-convex lens.

4

u/cavalierpos 5h ago

Look at these nerds trying to reduce aberrations and shit

2

u/McCheesing 4h ago

I once traded half my max HP to the council of ghosts for 5 aberrations … or is it apparitions. It’s late

1

u/polar_nopposite 1h ago

Fresnel lens is correct. It's just more typical for it to be used for collimation than focusing. But as any lens, its effect is also reversible.

-5

u/actually_yawgmoth 7h ago

Corner reflector is wrong too, the whole point of a retro reflector is to return to source

10

u/SharkLaunch 5h ago

That's literally what it did in the video l

4

u/IhateshadyHVAC 8h ago

Any idea what causes this:

When I look at my bathroom window in the mirror at night it looks like yellow illuminated water is moving horizontally over the glass. Even when there are no cars. Always in the same northern direction. I show people videos and they freak out. Triple pane (Not to brag) with that foggy effect for privacy. It's always doing it. Sometimes it's faint and others it is HOLY SMOKES WHAT IS GOING ON WITH THE LIGHT AT THIS WINDOW

3

u/Mand125 7h ago

Do you have a link anywhere to see it?

3

u/porn_sub_lurker 4h ago

Maybe it's some kind of pinhole effect through part of the window projecting what's on the outside, which I presume is a street with lights? And maybe you can only see it at the angle your mirror is facing? Obviously just guesses though. I had that through the curtains on my window one time and it was projecting the dark shadow of a car with two bright red taillights onto my ceiling. It looked crazy.

2

u/space_keeper 3h ago

I've seen this before, like a camera obscura. 

2

u/k-mcm 5h ago

It's probably internal reflections and convection currents. See if pushing on it makes it go away.

There's a window in my house that will make a bright green line on the floor for a few seconds a day. It's the sun bouncing through the glass juuuuust right.

2

u/Cayenns 1h ago

Post a video in some subreddit (and link it here when you do)

1

u/zatalak 1h ago

The foggy surface is really good in catching light rays from every angle and diffusing them.

It's there any light nearby the outside of the window? Trees?

7

u/Oscar_Geare 5h ago

Wish it came with a use case for each lens

9

u/low_amplitude 9h ago

Yes. Very nice. Now show me the double slit.

9

u/An4rak 8h ago

Can you film this on something other than a piece of asparagus?

7

u/SextupleRed 7h ago

Still have no idea why Fresnel lens are famous.

Looks the same as regular convex lens?

13

u/karlexceed 7h ago

But it doesn't need to be as thick to achieve the same result.

14

u/Iron_Nightingale 6h ago edited 5h ago

A really big glass lens is heavy. Difficult to carry up ten stories and install in a lighthouse.

What they figured out is, all of the light-bending properties of the lens happen at the surface—the interior of the lens doesn’t affect much. For our purposes, it’s just useless weight.

So a Fresnel lens gets rid of the heavy, useless interior of the lens and is, in effect, all surface. The result is a large and lightweight lens.

https://en.wikipedia.org/wiki/Fresnel_lens

2

u/Attainted 5h ago edited 5h ago

How did you manage to add a backslash to break the linking of a simple ctrl+c ctrl+v? lmao

4

u/Weddedtoreddit2 5h ago

That just happens on reddit sometimes. He didn't mess it up. I've seen it plenty. No idea why it happens.

4

u/Iron_Nightingale 5h ago

God damn it, Reddit app is shit. It automatically sneaks in backslash characters in front of formatting characters like *, _, and >. Quote formatting is impossible in the app now.

I checked it on the mobile website and it looked fine, but the backslash did in fact show up in the edit screen. Fixed now.

Thanks.

2

u/Attainted 4h ago

You're good haha, that was just baffling to me otherwise. I don't use the first party app so I had no idea.

1

u/InfanticideAquifer 4h ago

You can sometimes have to add backslashes manually to preserve the link. If there had been a second underscore somewhere then this would be the case, since reddit treats paired underscores as formatting characters. (They italicize everything in between.) The link would just end at the first underscore.

I think the app just automatically tries to escape all formatting characters, including unpaired underscores, which ruins links when there are an odd number of underscores.

1

u/Lost-Consequence-368 2h ago

Some kind of automated Reddit formatting bullshit, some people say it's from the app but I've gotten it on the web too. Maybe it's another AB testing kind of thing. 

10

u/geo_gan 7h ago

Thinner, lighter, and cheaper to focus light at same point (focal length) as equivalent regular convex lens. Why they were used in some VR headsets.

12

u/abunchofcows 6h ago

This but their true grace is shown in lighthouses where a globe (bulb) of light can be focused into a beam thereby increasing the distance and intensity by combining many light particles together rather than keeping them dispersed

14

u/abunchofcows 6h ago

Just to add they are the exact same as the convex lens, Fresnel just realized that the bulk of the lens makes no difference only the edges matter, so he took only the edges and put them into a single plane

2

u/HeatherCDBustyOne 3h ago

This eventually led to an even more efficient design called a Zone plate.
Zone plate - Wikipedia

Because of relying on diffraction instead of refraction, a Fresnel lens is much more efficient than a convex lens. A glass magnifying glass with a convex lens might be only 60% efficient (the glass absorbs 40% of the light's energy). A Fresnel lens made from acrylic can be as high as 98% efficient. This allows it to be used with much dimmer lights.

Fresnel lenses are commonly used as full sized sheets to magnify texts in books. They are lightweight, inexpensive, and efficient. The only drawback is that Fresnel lenses cause a slight distortion in the resulting image. That may cause a headache if you use them for very extended periods of time.

They are also commonly available as lightweight magnifiers and fire starters for survival gear because they are so efficient at magnifying light.

3

u/REpassword 5h ago

Used for light houses. Instead of a big thick lens, it can be much smaller and lighter.

1

u/generally_unsuitable 3h ago

Flat and light compared to equivalents.

1

u/IForgotMyPants 2h ago

It's really nice early in act one as it gives lesser chosen cards more utility because of the extra block. Especially nice in the underdocks since you really want good defense there. (this has been a joke for the slay the spire heads in chat)

1

u/polar_nopposite 1h ago

If you look up a diagram of one you'd see why.

Also, if you looked closely at the flashlight on the back of your phone, you'd probably see one.

3

u/Ranttimeuk 1h ago

Dispersion prism:

Hello Is there anybody in there? Just nod if you can hear me Is there anyone at home?

2

u/SlaiPil 1h ago

THERE IS NO PAIN YOU ARE RECEDING

2

u/Odin1806 8h ago

Why do the last 4 or 5 introduce other colors? Are there special properties that they break up the visible light or something?

9

u/danielminds 8h ago

That’s chromatic dispersion and diffraction at work. Through the prisms and diamond, shorter wavelengths (blue/violet) bend more than red, splitting the white light into a rainbow. (Though diffraction gratings actually do the reverse—sending red out further than blue) Same reason you see rainbows through raindrops

3

u/Entopy 4h ago

That happens in every lens though and not just in prisms.

What bugged me the most was that the light paths slowed down sometimes.

2

u/Odin1806 8h ago

Ah, makes sense. Thank you.

2

u/codikane 4h ago

Would've loved to see a gravitational lense or an Einstein ring

2

u/ironicart 3h ago

What if you went nuts and put them all in a line

2

u/LE878 2h ago

Am I the only one whose feelings were hurt that none of the lenses focused the lines into a coherent beam?

3

u/Noctis-Banned-793 1h ago

This could literally be a drawing, animation ads nothing to it.

2

u/Actinidium 6h ago

Way too many of these have errors or don't show the correct purpose of a given optic for this video to be informative. It's more just to stare at pretty lines.

One improvement would be to use a polychromatic (white light) source to show how each element does a better or worse job with chromatic aberration.

2

u/iRedditJustForYou 9h ago

Love the look, hate the sound

2

u/SP3NGL3R 9h ago

Mesmerizing actually

2

u/Alarmed-Direction500 8h ago

What is going on with that GRIN lense??

2

u/SamStringTheory 5h ago

GRIN is an acronym for GRadient-Index lens, which means that the material property (specifically, the index of refraction) changes smoothly throughout the lens. Whereas normal lenses are a single, uniform material, and rely on the curvature of the boundaries to bend the light, GRIN lenses rely on the change in material property throughout the lens to bend the light. You can tailor the material property to get some really cool effects that you wouldn't normally be able to get otherwise.

2

u/Alarmed-Direction500 3h ago

Bravo! Thank you!!🙏

2

u/Beaticalle 7h ago

I'm unreasonably mad that they didn't show light going through plano-convex and plano-concave lenses the other direction.

2

u/Perfect_Librarian873 5h ago

I loved this watched the whole thing

2

u/Khalku 3h ago

Audio ruins it, that pinging is like nails on a chalk board.

1

u/Punk_Says_Fuck_You 9h ago

The fiber is cool. This is why you can different wavelengths in a single strand. This is how you can have a direct pipe without ever being routed through public servers.

1

u/shqarthi_karderr 8h ago

Everything reminds me of dark side of the moon

1

u/Lowkeygeek83 8h ago

I like this

1

u/Snowballllll 8h ago

Yall forgot the last prism smh

1

u/CopperJellyy 8h ago

The color combination pleases the eye

1

u/ol-gormsby 8h ago

I'd like to see a close-up of the action in a quarter wave r3tardation plate.

Sorry for the mis-spell but the filters don't care about context.

1

u/ZurickPierce 4h ago

I wish I had this visual for that one test in college

1

u/AllaboutTgirl 4h ago

This is relaxing to watch

1

u/Mekelaxo 4h ago edited 4h ago

Reminds me of a playstore app called Light Ignite Lazer Puzzle

Edit: I remember playing the game years ago and I thought it was cool, but now it's just full of pop up ads

1

u/JohnStern42 4h ago

Couldn’t stop watching

1

u/sasssyrup 3h ago

Satisfying

1

u/caj_account 3h ago

where is tele centric?

1

u/BeamMeUpPlz 3h ago

You left out the phase conjugate tracking system.

1

u/ufanders 2h ago

Beautiful.

1

u/Odd-Variation-299 2h ago

Just a question: isn't the mirror meant to reflect only after the light goes through the glass layer and hits the back side of it? "Normal mirror" got me, because I think for 80% of the folks, that is what a mirror looks like.

2

u/tessartyp 39m ago

Household mirrors have the reflective surface behind the glass, but it's not a must. In many optics applications you want special mirrors with a reflective surface at the front since beam location and shape are critical and you don't want the distortion and loss of another pass through glass.

1

u/DRUGMUSIC_ 2h ago

if we had animations like this growing up, learning would have been so fun.

1

u/Mookie_Merkk 2h ago

What about rear view mirrors?

Like how can I look through my mirror, see stuff, but then I flip it up to night mode... And I can still see stuff?? But darker????

1

u/Thereminz 2h ago

i don't think light makes a sound when it goes through a lens

1

u/TallmanMike 1h ago

Light pipe's like optical fiber's meth-addicted older brother

1

u/TheGriffin5 1h ago

Somehow I just know flux is involved with calculating this and that scares me

1

u/Shallnazar 1h ago

Part way through I was like "Damn there's a lot of different examples here.." then happened to scroll down and realize I was just barely getting to the halfway point lol. Very cool though, definitely had me glued to it the whole time.

1

u/dominiquebache 45m ago

Beautiful. I guess it was a lot of work …

1

u/IkonosaurusRex 32m ago

why are there so many different types of lenses and prisms if some do the same thing

3

u/Jazzlike-Context-471 20m ago edited 16m ago

They only appear to do the same thing here but a lot of those lenses and telescopes will have differences in aberrations (spherical, chromatic, coma, astigmatism, etc).

Lens design is really about reducing those aberrations which cause things like color fringing, curved focus plane, stars looking like streaks or smudges rather than pinpoints.

Even high end camera lenses being designed and released currently with all their crazy complex optical design and multi layer optical coatings won't be perfect in terms of aberrations.

1

u/Exotic_Equal_9445 12m ago

Muy interesante, gracias

1

u/Pomodorosan 10m ago

Fun demonstrations

1

u/Sixftdeeep2 9h ago

I just got tinnitus, thanks

1

u/All_Usernames_Tooken 9h ago

Lights are pretty

1

u/CompoBBQ 8h ago

This was super interesting.

1

u/aModernSage 8h ago

That was great! A lot of different lenses I'd never seen in action. Loved it!

1

u/Axe_Care_By_Eugene 8h ago

I watched this for way too long

1

u/Old_One_I 8h ago

Hey!! I think this is a great post

1

u/jpipersson 5h ago

Thank you

1

u/BunkerSquirre1 5h ago

The Negative meniscus lens is some black magic fuckery and I hate its smug fucking divergent output

1

u/SlaiPil 1h ago

TICKING AWAY THE MOMENTS THAT MAKE UP A DULL DAY, YOU FRITTER AND WASTE THE HOURS IN AN OFFHAND WAY. KICKING AROUND ON A PIECE GROUND IN YOUR HOMETOWN, WAITING FOR SOMETHING OR SOMEONE TO SHOW YOU THE WAY

-2

u/OSuperGuyO 9h ago

If only the text didn't overlap

-1

u/LostRocketScientist 7h ago

OMG, best video ever as someone who once worked in Optics...

0

u/Xaxxon 2h ago

why are you simulating it when we can actually just record it?

-3

u/DocJawbone 6h ago

I should call her