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Cameras and Lenses

ciechanow.ski

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Re: Cameras and Lenses

#91

Post by lodi »

The_Colonel wrote: post #35

I have a question for the more knowledgeable: Color filters on the sensor split the light into three wavelength ranges - red, green, blue. Then photosites measure intensity of light, which means that sensor only knows that the incoming photon is "roughly green", but doesn't actually recognize its precise wavelength. So e.g. when the light is pure orange, it falls down into red wavelength range and is counted as red.…

> So e.g. when the light is pure orange, it falls down into red wavelength range and is counted as red.

If you only work with one photon at a time, then yes, you don't know if the photon passing through the filter was red, or orange, or with smaller probability even green or blue. But when you have trillions of photons passing through, you can "see" the difference by the relative intensity of light.

Remember that at the quantum level, things don't happen deterministically; you have to consider the probability that a given outcome occurs. So the photon has a certain probability to hit the filter and get absorbed, a certain probability to pass through the entire depth of the filter, a certain probability to hit the sensor without generating an event, a certain probability to hit the sensor and initiate a chemical reaction (for film or biological eyes) or an electron cascade (for CCD sensors), a certain probability to quantum tunnel to the other side of the universe...

So getting back to your question, when pure orange photons hit a red filter, many of them will make it through the filter, but not as many as if they were pure red photons. When pure orange photons hit a green filter, some of them will make it through, but not as many as if they were pure green photons. So if your brain knows what the "white point" of a given environment is, relative to that white color it'll see a specific combination of "some red, some green" as orange. (Of course, if known-to-be-white objects are already orange--like when you put on amber ski googles--your brain will eventually adjust and recalibrate to perceive that color as something else... perception is tricky!)

Re: Cameras and Lenses

#92

Post by udev »

Brilliant work.

It really helps building an intuitive foundation of these phenomena.

With such intuitive foundation, one has confidence to look into the math behind the curtain, even if this math gets complex, you will still feel confident.

IMO, this kind of explanations is the correct way to start teaching anything.

Re: Cameras and Lenses

#94

Post by nodoodles »

_def wrote: post #87
nodoodles wrote: post #6

Impressive work! Nit on design: in first ~3 attempts to scan through the page to see if it is worth reading, i found myself stopping very early when the black background started given it usually signals a footer and end of useful content. The only reason I ended up discovering there is more content was the sanity check that if it is HN front news there has to be more to it :)

Maybe this should make you think about your "worthiness" scan ;)

Agree it is imperfect but there is too much Internet, too little time in life, therefore fast heuristics and patterns are useful :)

Re: Cameras and Lenses

#95

Post by baq »

echelon wrote: post #75
h_spacer wrote: post #58

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/Slavic_name_suffixes Hope that helps.

I'm still going to use they/them because a name doesn't necessarily match with one's gender.

language 1 extracts gender to a separate word.

language 2 embeds gender in the word itself.

names are words.

it's a lose-lose situation: native speakers of language 2 will look at what you wrote and cringe or just assume you're ignorant. they won't get the point you're trying to make, null, nada, 0% chance. source: i'm a native speaker of language 2.

Re: Cameras and Lenses

#97

Post by moron4hire »

throwaway98797 wrote: post #86
echelon wrote: post #79

Earlier quoted context omitted.

> The site is the work of a guy, "him", and "his" work. We don't have to guess and say "them" and "their" work. Assumptions are presumptuous and harmful. Everyone is a they/them until otherwise stated. These are extremely useful pronouns. You're a they/them. Calm down. You seem to be overly attached to regressive labels. I don't know what drives this in you, but the universe is burning and people just want to be happ…

“They” is historically understood to be plural. Some information fidelity is lost if “they” can mean multiple people and a person. Language is hard, so I understand the need for compromise. “Zee” could be used to avoid gender centric labeling while maintaining language clarity.

That is not true. Singular they has been in use as long as plural they. It has always been understood to be usable in either situation.

Re: Cameras and Lenses

#98

Post by jrockway »

The_Colonel wrote: post #35

I have a question for the more knowledgeable: Color filters on the sensor split the light into three wavelength ranges - red, green, blue. Then photosites measure intensity of light, which means that sensor only knows that the incoming photon is "roughly green", but doesn't actually recognize its precise wavelength. So e.g. when the light is pure orange, it falls down into red wavelength range and is counted as red.…

If you tried to turn the sensor data into light again, there would not be enough information to do so accurately. Everything is built around human perception of color. When a photon hits your eye, it produces a "tristimulus value" for your brain. (The tristimulus is produced by "S", "M", and "L" sensitive-cones; these roughly correspond to blue, green, and red; that's why those colors are what we use for base colors. But, you can use other colors, and you could use more than 3 if you wanted to. There is no law of the universe that splits colors into red/green/blue parts... that's just a quirk of human anatomy.)

The goal of a digital camera is to be sensitive to colors in the same way that your eyes are. If that tristimulus can be recorded and played back, your brain won't know the difference. The colors your monitor emits when viewing a photograph could be totally unrelated to what was in the original scene, but since your brain is just looking for a tristimulus, as long as that same tristimulus is produced, you won't be able to tell the difference.

(Fun fact -- there are colors you can see that don't correspond to a wavelength of light. There is no single wavelength of light that fully stimulates your S and L cones, but plenty of things are magenta.)

TL;DR: computerized color is basically hacking your brain, and it works pretty well!

Re: Cameras and Lenses

#99

Post by [deleted] »

moron4hire wrote: post #97
throwaway98797 wrote: post #86

Earlier quoted context omitted.

“They” is historically understood to be plural. Some information fidelity is lost if “they” can mean multiple people and a person. Language is hard, so I understand the need for compromise. “Zee” could be used to avoid gender centric labeling while maintaining language clarity.

That is not true. Singular they has been in use as long as plural they. It has always been understood to be usable in either situation.

[deleted]

Re: Cameras and Lenses

#100

Post by franga2000 »

h_spacer wrote: post #50
franga2000 wrote: post #24

Earlier quoted context omitted.

But it's way less effort than checking, isn't it? The name in the footer isn't English, so it's hard to know from that and there's no about page that I could find. The Twitter profile makes it more obvious, but I only clicked on it to check because of your comment. Why bother??

Slav surnames are gendered. * ski is male, * ska is female, * sko is neutral. Using gender neutral in this case is as insulting as calling him a dog. Other cases where using gender neutral pronouns insults everyone speaking the language is using Latinx for Latino. If you want to butcher every other languages genders like they are in English, use Latin instead - the gender neutral form of Latino in English since only…

I'm from Slovenia and this is bullshit. Maybe it holds true in a couple of Slavic languages, but I'm familiar with a handful of them and this isn't a thing in any of those.

Regarding the "insulting" part, you're probably mistranating it. What would be insulting in many Slavic languages is using the "middle grammatical gender" (rough literal translation) which is equivalent to using "it" to refer to a person in English. If you insist on translating literally, using third person gender neutral (in Slovene and many Slavic languages) is actually a sign of respect and is how talks to their superiors (antiquated in 3rd person, but still the norm in 2nd).

Not that it matters anyways, as we're all talking in English and thus English grammar is the only one that matters. Even if you know for a fact all parties in the conversation speak the other language, if you're using English, the rules of the other language don't matter.

P.S. Re: Latinx: yeah, that's stupid and I'd see it as mildly offensive if directed at me, but that is neither a pronoun nor common practice, so is entirely irrelevant here

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