/sci/ - Science & Math » Thread #13835265

5KiB, 287x176, 1636264851219.jpg

View Same Google iqdb SauceNAO

Optic bandpass filters

Anonymous Tue 09 Nov 16:17:44 2021 No.13835265 View Reply Original Report

Quoted By: >>13835556 >>13835812 >>13836441 >>13838607

If I have an optical bandpass filter for say 620-660nm, will anything not that color appear black / can't see it?

What will I actually see through that lens?

Anonymous

View Same Google iqdb SauceNAO ComfyCha.jpg, 543KiB, 1280x960

Anonymous Tue 09 Nov 2021 18:29:33 No.13835556 Report

Quoted By: >>13835797

>>13835265
>will anything not that color appear black / can't see it?
Correct. Just as in a darkened room it is dark because you cannot see thermal infrared. Had you been able to see thermal infrared, the room would have been bright.

Anonymous

Anonymous Tue 09 Nov 2021 20:05:33 No.13835797 Report

Quoted By: >>13835865

>>13835556
Just to make sure I understand you correctly...
Hypothetical:
I have an object that is that exact color of the nanometer range that is unfiltered say it's only like 3 nanometers unfiltered.

Everything else in the room is normal but nothing is that particular shade of let's say yellow.

Everything else in the room would be solid black and that single object would be the only thing visible through the lens?

Or with the other objects still be visible but incredibly faint because of them having a little bit of bleed over into that nanometer range regardless of what color they are?

Anonymous

View Same Google iqdb SauceNAO bandpass-filter-fig-1.png, 63KiB, 1298x732

Anonymous Tue 09 Nov 2021 20:08:57 No.13835812 Report

Quoted By: >>13835828

>>13835265
C'mon, man.

Anonymous

Anonymous Tue 09 Nov 2021 20:13:15 No.13835828 Report

Quoted By: >>13835835 >>13835844

>>13835812
>only shitty rc filters exist

Anonymous

View Same Google iqdb SauceNAO bxza.jpg, 33KiB, 475x284

Anonymous Tue 09 Nov 2021 20:18:27 No.13835835 Report

Quoted By:

>>13835828
C'mon, man.

Anonymous

View Same Google iqdb SauceNAO nigs steal.png, 654KiB, 818x767

Anonymous Tue 09 Nov 2021 20:20:44 No.13835842 Report

Quoted By:

Anonymous

View Same Google iqdb SauceNAO sketch-infrared.gif, 16KiB, 630x383

Anonymous Tue 09 Nov 2021 20:21:12 No.13835844 Report

Quoted By:

>>13835828
...C'...c'mon, man?

Anonymous

Anonymous Tue 09 Nov 2021 20:26:48 No.13835865 Report

Quoted By: >>13835896

>>13835797
>Everything else in the room would be solid black and that single object would be the only thing visible through the lens?
No, because normal everyday objects normally reflect a large range of wavelengths.
To be clear: an optical bypass filter ONLY transmits light within a given range of wavelengths/frequencies. If and only if an object does not reflect any of these frequencies (this would be uncommon but not impossible), then it appears black through the filter.

Anonymous

Anonymous Tue 09 Nov 2021 20:36:46 No.13835896 Report

Quoted By: >>13836033

>>13835865
So say I have three objects in front of me a yellow red and blue object

I'm looking at them through a lens that is only allowing a very narrow range of the yellow frequency

Would I simply see all three objects as yellow? Would I be able to distinguish the originally yellow one from the other two would it be vastly brighter or something?

I apologize for the stupid questioning I'm really having a hard time understanding this physically and I'm trying my best.

Anonymous

View Same Google iqdb SauceNAO 719590main_Grid-Sun-orig_full (1).jpg, 2MiB, 2048x2048

Anonymous Tue 09 Nov 2021 21:23:50 No.13836033 Report

Quoted By: >>13836339 >>13837417

>>13835896
Bro, this is a "how red is red" question.

Your brain is effectively RGB-ish, so the fact you use "yellow frequency" is kind of interesting, since "yellow frequency" is not a peak your retina can detect.

>Would I be able to distinguish the originally yellow one from the other two would it be vastly brighter or something?
Here is an easy answer. Don't think of this in terms of lenses. You will just confuse yourself.

You're asking questions that are syntactically correct but kind of mean nothing. You want answers to questions that maybe you should reformulate.

Anonymous

Anonymous Tue 09 Nov 2021 23:41:27 No.13836339 Report

Quoted By: >>13836346 >>13838639

>>13836033
I have literally no understanding besides basic logic of the subject so my thinking was if the light is being distributed evenly amongst the objects if one of them appears to be yellow then it is I assume reflecting more of that wavelength off of it so say 70% of the energy being reflected off of it we perceive as yellow while the blue one only has a little bit of yellow say like 10% so when I put a filter over to ignore everything besides that yellow I guess that I would see one vastly more bright or clearly than the other one simply because there's more of that wavelength of being reflected off of it.

How wrong am I?

Anonymous

Anonymous Tue 09 Nov 2021 23:44:36 No.13836346 Report

Quoted By: >>13836384

>>13836339
Wavelength? What's waving?

Anonymous

View Same Google iqdb SauceNAO LIS_SCI_ART_02_Colours_of_light_ (...).jpg, 97KiB, 780x519

Anonymous Wed 10 Nov 2021 00:09:47 No.13836384 Report

Quoted By: >>13836441

>>13836346
Am I missing something here?

Anonymous

Anonymous Wed 10 Nov 2021 00:48:42 No.13836441 Report

Quoted By: >>13837417 >>13838305 >>13839276

>>13836384
>>13835265
>What will I actually see through that lens?
>So say I have three objects in front of me a yellow red and blue object
Is there a nuclear explosion behind them while you're looking at the objects?

>I have an object that is that exact color of the nanometer range that is unfiltered say it's only like 3 nanometers unfiltered.

>Everything else in the room is normal but nothing is that particular shade of let's say yellow.

>Everything else in the room would be solid black and that single object would be the only thing visible through the lens?

>Or with the other objects still be visible but incredibly faint because of them having a little bit of bleed over into that nanometer range regardless of what color they are?

The answers to your question is, "But do you believe in quantum mechanics?"

Anonymous

Anonymous Wed 10 Nov 2021 08:58:09 No.13837417 Report

Quoted By: >>13838619 >>13839251

>>13836033
This seems confused. The RGB properties of the eye comes after the filtering.
Thus a monochromatic red, yellow and blue object seen through a yellow bandpass filter, will let you see the yellow object, while the red and blue objects are masked out.

>>13836441
What does this even mean?

Anonymous

Anonymous Wed 10 Nov 2021 16:17:38 No.13838305 Report

Quoted By: >>13838619

>>13836441
Are you off your medication?

Anonymous

Anonymous Wed 10 Nov 2021 18:24:01 No.13838607 Report

Quoted By:

>>13835265
Yes everything would appear black outside of the 620-660 band. However, if you actually held your eye up to it, you would probably just see a reflection of your eye because everything outside of the band is reflected.

Anonymous

View Same Google iqdb SauceNAO radioactive-uranium-ore-640x533.jpg, 153KiB, 640x533

Anonymous Wed 10 Nov 2021 18:28:00 No.13838619 Report

Quoted By:

>>13837417
>>13838305
Because I know how reality works.

>>Everything else in the room is normal but nothing is that particular shade of let's say yellow.

Cool story, bro.

Anonymous

Anonymous Wed 10 Nov 2021 18:35:10 No.13838639 Report

Quoted By: >>13838807

>>13836339
when thinking about bandpass filtering just think in monochromatics, like a black and white tv

I think what youre really trying to ask is how the scene would actually look. Anything reflecting yellow light will appear lit through your filter, everything else will be dark. if you have objects in front of you, with any light source, there will be all three colors being projected everywhere. throw on a perfect yellow filter and now you see only the yellow light instead of any of the other reflected colors. Yes, objects dont only reflect light as the color they are, a blue balloon will reflect yellow, and it will let some in too, and some will also be refracted.

Anonymous

Anonymous Wed 10 Nov 2021 19:43:29 No.13838807 Report

Quoted By: >>13839055

>>13838639
>I think what you're really trying to ask is how the scene would actually look.
Yes thank you, this is exactly what I'm asking, that was my OP explicitly
>What will I actually see through that lens?

>Yes, objects don't only reflect light as the color they are, a blue balloon will reflect yellow, and it will let some in too, and some will also be refracted.

That's how I'm understanding it, mainly I'm curious if say that blue balloon next to a yellow balloon would be either.

1. be no different, yellow and blue balloon looking the same

2. less "yellow" and more, I guess greyish yellow? (speaking about you talking about being monochromatic) than the yellow balloon while the yellow balloon is unchanged.

3. some other thing I'm too stupid to figure out.

Anonymous

Anonymous Wed 10 Nov 2021 21:24:26 No.13839055 Report

Quoted By: >>13839098

>>13838807
>2. less "yellow" and more, I guess greyish yellow? (speaking about you talking about being monochromatic) than the yellow balloon while the yellow balloon is unchanged.
this one, imagine a black and white TV but white is yellow. The filter will give you a yellow-monochrome image. The blue balloon will be displayed in darker shades of yellow, that being whatever little yellow light it reflected. It wouldn't be a bandpass filter if it also let through blue light. Most 'optical bandpass' filters you find in real life aren't perfect and will convert some other colors of light into the targeted frequency. I dont think it's impossible to have something make a scene appear a different color than it really is by averaging every frequencies intensity, but that wouldn't be a bandpass filter bro.

Anonymous

Anonymous Wed 10 Nov 2021 21:35:58 No.13839098 Report

Quoted By: >>13839167 >>13839267 >>13839675

>>13839055
Maybe I'm just asking about the wrong filter desu.
Basically what I'm looking for is a lens that will either eliminate or at the very least differentiate something that is 1 particular color from everything around it

Anonymous

View Same Google iqdb SauceNAO Dark_Side_of_the_Moon.png, 4KiB, 300x300

Anonymous Wed 10 Nov 2021 21:54:06 No.13839167 Report

Quoted By: >>13839175

>>13839098
>lens
Stop saying lens if you mean filter.
>or at the very least differentiate something that is 1 particular color from everything around it
Are you trolling us? I think you missed the starting gun, bro.

Anonymous

Anonymous Wed 10 Nov 2021 21:55:49 No.13839175 Report

Quoted By: >>13839200

>>13839167
>Stop saying lens if you mean filter.
>Are you trolling us? I think you missed the starting gun, bro.
I said I don't know anything on the subject, I'm asking a simple question if the answer is it doesn't exist, then that's it

Anonymous

Anonymous Wed 10 Nov 2021 22:01:51 No.13839200 Report

Quoted By: >>13839236

>>13839175
If you want to build intuition, look up fluorescence photography, and maybe chlorophyll a florescence photography specifically.

Your questions are like if someone asked a philosopher, "But why can't I kill them if they make me feel bad?" What's a philosopher supposed to say to this question? He probably pushes a red button under his desk.

If you are not trying to understand something technical with this information, you're really wasting time. And so, look up some fluorescence photography examples and DIY shit.

Anonymous

Anonymous Wed 10 Nov 2021 22:14:04 No.13839236 Report

Quoted By: >>13839251 >>13839276 >>13839281 >>13839303

>>13839200
I'm asking for what would physically happen if I got one of these lens, and looked through it. That's it

If you don't know, you don't know.

It's not a philosophical question, it's a very exact question. What will I see if I use one of these lens.

Anonymous

Anonymous Wed 10 Nov 2021 22:17:56 No.13839251 Report

Quoted By:

>>13839236
The answer is here: >>13837417

Anonymous

View Same Google iqdb SauceNAO q7f6XBXv.png, 689KiB, 640x635

Anonymous Wed 10 Nov 2021 22:23:55 No.13839267 Report

Quoted By:

>>13839098
to do that you subtract the unfiltered image from the filtered image and the subject matter you're interested in jumps outs

Anonymous

Anonymous Wed 10 Nov 2021 22:26:46 No.13839276 Report

Quoted By: >>13839326

>>13839236
>It's not a philosophical question, it's a very exact question.

>>13836441
>"But do you believe in quantum mechanics?"

>>13839236
>What will I see if I use one of these lens.

NPC identified.

Anonymous

Anonymous Wed 10 Nov 2021 22:27:55 No.13839281 Report

Quoted By: >>13839303 >>13839371

>>13839236
The transmission wavelength is dependent on viewing angle for thin-film filters. However, assuming you're viewing a perfect dual brickwall bandpass filter head on, you will of course only be able to see the frequencies allowed by the filter. Everything else will be black. In reality, nothing perfectly absorbs a single frequency. So even a red object will still reflect a tiny amount of other colors that would make it through the filter if illuminated by a black body source like the sun. The effect would be more pronounced if the things you're viewing were illuminated with a discrete set of frequencies, say from fluorescent lighting.

Anonymous

Anonymous Wed 10 Nov 2021 22:34:56 No.13839303 Report

Quoted By:

>>13839281
This guys gets it.

>>13839236
Just to be a faggot, let's pretend you stand in front of a wall which is a perfect filter that only allows 440 +-1 nm to pass.
You turn on your radio.
Do you hear a radio station or white noise or no sound?

Anonymous

View Same Google iqdb SauceNAO unknown.png, 35KiB, 400x197

Anonymous Wed 10 Nov 2021 22:38:59 No.13839326 Report

Quoted By: >>13839332

>>13839276
What the actual fuck do you even mean by this?

Anonymous

Anonymous Wed 10 Nov 2021 22:42:11 No.13839332 Report

Quoted By:

>>13839326
It means you cannot imagine things.

Anonymous

Anonymous Wed 10 Nov 2021 22:49:41 No.13839371 Report

Quoted By: >>13839554 >>13839599

>>13839281
thank you, I only have 1 single question in relation to this part
>Everything else will be black. In reality, nothing perfectly absorbs a single frequency. So even a red object will still reflect a tiny amount of other colors that would make it through the filter if illuminated by a black body source like the sun.

The "lesser" reflected light from the object that is not the "allowed filtered frequency" but is still giving off some of the allowed frequency
example a red object in a yellow filter
How would they appear to your eye? if I understand right and it's just monochromatic.

is it basically a sliding scale from black to yellow? and the yellow object being on the far right end (yellow) and the say red object is somewhere in the middle depending on how much yellow light is reflecting?

Anonymous

Anonymous Wed 10 Nov 2021 23:37:43 No.13839554 Report

Quoted By: >>13839599 >>13839644

>>13839371
>example a red object in a yellow filter
>How would they appear to your eye?
As a very dim yellow. How dim depends on the pigment.
>is it basically a sliding scale from black to yellow? and the yellow object being on the far right end (yellow) and the say red object is somewhere in the middle depending on how much yellow light is reflecting?
Essentially, yes.

Anonymous

View Same Google iqdb SauceNAO filter_1.jpg, 196KiB, 1000x400

Anonymous Wed 10 Nov 2021 23:49:09 No.13839599 Report

Quoted By: >>13839644

>>13839554
>>13839371

Why do I do what I do?

Anonymous

Anonymous Thu 11 Nov 2021 00:04:16 No.13839644 Report

Quoted By: >>13839666

>>13839554
>>13839599
Thank you, what is the original photo?

Because when people ask questions related to something you know that show a genuine interest in figuring something out no matter how stupid they are you feel inclined to help.

Anonymous

Anonymous Thu 11 Nov 2021 00:11:11 No.13839666 Report

Quoted By: >>13839772

>>13839644
http://lichtmeister.blogspot.com/2011/01/spice-up-you-bw-photography-with.html
>red habanero against a bed of green parsley

If I weren't to lazy to find my fluorescence pictures I would have posted some cool shit but who has time for that? This isn't /p/

Anonymous

View Same Google iqdb SauceNAO 2880px-Czerny-Turner_Monochromat (...).png, 354KiB, 2880x1786

Anonymous Thu 11 Nov 2021 00:13:25 No.13839675 Report

Quoted By: >>13839685

>>13839098
>Basically what I'm looking for is a lens that will either eliminate or at the very least differentiate something that is 1 particular color from everything around it
this apparatus is pretty much the only analog way to do it. Otherwise you're using a camera and an algo to subtract the color you dont want.

Anonymous

Anonymous Thu 11 Nov 2021 00:16:32 No.13839685 Report

Quoted By: >>13839707

>>13839675
This is cool. It's cool seeing a complete schematic you only half bothered to complete in your mind.

Very nice. Saved.

Anonymous

Anonymous Thu 11 Nov 2021 00:23:18 No.13839707 Report

Quoted By: >>13839736

>>13839685
>a complete schematic you only half bothered to complete in your mind.
google translate?

Anonymous

Anonymous Thu 11 Nov 2021 00:33:00 No.13839736 Report

Quoted By:

>>13839707
Once I imagined chromatic aberration, I knew there was a way to eventually get the image for whatever color you wanted, so I didn't bother continue drawing the diagram in my head.

Anonymous

Anonymous Thu 11 Nov 2021 00:49:08 No.13839772 Report

Quoted By:

>>13839666
>I would have posted some cool shit but who has time for that?
>666
I think satan wants these posted

Capcode	All Only User Posts Only Moderator Posts Only Admin Posts Only Developer Posts
Show Posts	All Only With Images Only Without Images
Deleted Posts	All Only Deleted Posts Only Non-Deleted Posts
Ghost Posts	All Only Ghost Posts Only Non-Ghost Posts
Post Type	All Only Sticky Threads Only Opening Posts Only Reply Posts
Results	All Grouped By Threads
Order	Latest Posts First Oldest Posts First

Your latest searches