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on Gopher (inofficial)
HTML Visit Hacker News on the Web
COMMENT PAGE FOR:
HTML Cameras and Lenses (2020)
fluorinerocket wrote 1 hour 58 min ago:
Awesome, I learned something about optics! I was afraid this was going
to be about Haskell
Yaggo wrote 6 hours 0 min ago:
The content is gold but so is the web page design.
ChrisMarshallNY wrote 12 hours 58 min ago:
This guy's stuff is always so awesome.
Thanks for sharing it!
plasticeagle wrote 13 hours 13 min ago:
Incredible. Not a whiff of AI (I mean, obviously I see now because it's
from 2020). Just fantastic to see clear and elegant writing again.
o10449366 wrote 11 hours 47 min ago:
Comments on AI, on an article which has nothing to do with it, are
just as uninspired as AI writing.
pontussw wrote 15 hours 22 min ago:
This is so incredibly well done
brcmthrowaway wrote 16 hours 6 min ago:
Does anyone know of a lens that can make a laser look like a spotlight?
dekhn wrote 13 hours 12 min ago:
More details required.
Like the other comment says, this can be done with a beam-expanding
telescope (which can be as simple as two lenses whose focal length
ratios determine the magnification). [1] and [2] are a good place to
start.
But it can be a bit more complicated than that , and it's often
easier to use an LED.
HTML [1]: https://www.newport.com/n/how-to-build-a-beam-expander
HTML [2]: https://www.thorlabs.com/an-example-of-a-diy-keplerian-beam-...
aj7 wrote 15 hours 58 min ago:
Look up âbeam expanding telescope.â
plagiarist wrote 16 hours 30 min ago:
What a fantastic article!
Makes me wish for a similar resource that would teach 3+ element
optics, moving elements, and sortof get closer to modern lens design.
nntwozz wrote 16 hours 41 min ago:
Bartosz Ciechanowski's blog brings back the joy of surfing the web
during the heyday of Adobe Flash (minus the 100% CPU).
It's so much fun manipulating things, exploring and getting surprising
feedback.
I know it's not really fair to compare this highly scientific
masterpiece to the artistic flash websites of the past, but for me at
least it immediately evokes the same feelings.
zbendefy wrote 16 hours 27 min ago:
Tangential, but Flash had a nice side effect that the "app" could be
exported in a self contained way via SWF.
Exporting this site for example in a future proof way is not that
obvious. (Exporting as pdf wont work with the webgl applets,
exporting the html page might work but is error prone depending in
the website structure)
50 years from now, flash emulators will still work on swf files, but
these sites might be lost. Or is there a way to archive sites like
this?
pava0 wrote 3 hours 20 min ago:
I strongly suggest you try (the selfhosted version of) Browsertrix
from Webrecorder, it's really well done, actively delevoped and can
export the website as .wacz without problem.
KPGv2 wrote 11 hours 38 min ago:
> 50 years from now, flash emulators will still work on swf files
I'm not sure 50 years from now there will be flash emulators. Who
is going to write on for the XP3.12345235 Fruity Ununpentium
Silicon x256^2 neuralink devices.
Didn't Flash die because iPhones weren't going to support it? So
one of the major OSes people spend most of their lives on can't
even run SFW files. Can Android? I've honestly never tried.
But web standards persist.
roywiggins wrote 6 hours 25 min ago:
Ruffle, the Flash runtime emulator, does run in the browser.
sneak wrote 9 hours 30 min ago:
50 years from now there will be emulators that can run the OSes
of today that can run flash emulators.
KPGv2 wrote 13 hours 14 min ago:
> Or is there a way to archive sites like this?
A couple days ago, someone published their archive of HN that works
in any browser.
Archiving sites is easy anyway. I wrote a Scrapy app that archives
everything within the a specific fandom on Ao3. TH hardest part is
remembering how beautiful soup queries work.
roywiggins wrote 13 hours 7 min ago:
Static sites are straightforward, yeah. Highly dynamic websites
like this one commonly explode when you archive them naively.
sneak wrote 9 hours 29 min ago:
There is nothing dynamic about this site in the sense of
âstatic siteâ. This may well be a static site.
roywiggins wrote 6 hours 31 min ago:
Wikipedia, at least, uses the same terminology as me: [1] > A
client-side dynamic web page processes the web page using
JavaScript running in the browser as it loads.
The linked page is one of those. They're often harder to
scrape than server-side rendered webforums and the like.
HTML [1]: https://en.wikipedia.org/wiki/Dynamic_web_page?wprov...
mrkstu wrote 12 hours 37 min ago:
Server side rendered sites that are dynamic in nature- you'll
only get a literal snapshot of state you happen to be in...
roywiggins wrote 12 hours 32 min ago:
I mean highly dynamic, entirely frontend sites like these are
hard to archive, since you have to really preserve every bit
of JavaScript dependency, including any dynamically loaded
dependencies, and rewire everything to work again.
And then hope that whatever browser features you rely on
aren't removed in 20 years. Flash applets from 20 years ago
are usually more self-contained and Just Work if you have a
functioning runtime (either the official one or Ruffle)
scosman wrote 16 hours 46 min ago:
If anyone hasn't already seen Bartosz's mechanical watch animations,
they are also amazing:
HTML [1]: https://ciechanow.ski/mechanical-watch/
fsckboy wrote 16 hours 47 min ago:
Cameras and Lenses and photography has been such a fascinating and open
and do-it-yourself tinkering medium for well over a century: when are
we going to get to be able to play around with what's inside iPhone,
Samsung, and Pixel cameras?
(maybe we already can, I'm simply asking)
fsckboy wrote 16 hours 56 min ago:
> ̶P̶i̶c̶t̶u̶r̶e̶s̶ ̶h̶a̶v̶e̶ Art has always been a
meaningful part of the human experience. From the first cave drawings,
to sketches and paintings, to modern photography, weâve mastered the
art of recording what we ̶s̶e̶e̶ think and feel.
Sharlin wrote 16 hours 16 min ago:
Your "correction" does not make sense. "Pictures" and "art" are
overlapping categories but neither is a subset of the other. Pictures
in and of themselves are plenty fascinating to humans, without
bringing art into the equation.
fsckboy wrote 14 hours 25 min ago:
it is your critique that does not make sense. I was not applying
any hierarchy or subsetting whatsoever. Inseparable unity would be
closer to the point.
I was making the point that the cave painters believed everything
including rocks and trees were deeply invested with spiritual
power, and they didn't draw a cave painting without investing it
with spiritual ideas. Even if one of their goals was to capture an
accurate image of some animals, and indicate when in the lunar or
solar cycle they were expected to calve, when they went hunting for
one a part of the goal would be cut out its heart and eat it raw
because of the power contained within, and give thanks to the great
mother. Inseparable.
even though I am not spiritual at all, I find your worldview too
barren to explain human endeavor.
Sharlin wrote 13 hours 20 min ago:
I still don't know what your comment has to do with the article
at hand. If you want to branch the conversation to animism and
spirituality, I guess that's fine (although rather far-fetched
and arguably off-topic) but you should probably do it in a way
that actually offers some insight.
fsckboy wrote 12 hours 44 min ago:
i was replying to someone else's comment, their comment was to
the article. I was not replying to the article.
dpark wrote 13 hours 43 min ago:
> I was making the point that the cave painters believed
everything including rocks and trees were deeply invested with
spiritual power, and they didn't draw a cave painting without
investing it with spiritual ideas.
Nonsense. We donât know what prehistoric cave painters
believed.
> when they went hunting for one a part of the goal would be cut
out its heart and eat it raw because of the power contained
within
Do you have a pointer to the cave paintings that show hunting
animals at certain times in the lunar cycles and eating their
hearts raw to harvest this power? Because this sounds made up.
Also this says nothing about art.
fsckboy wrote 12 hours 39 min ago:
>Nonsense. We donât know what prehistoric cave painters
believed.
you need to study a bit more history, psychology, anthropology,
etc., you have absolutely no reason to believe they thought
anything different than we do today and what today's hunter
gatherers believe. the evidence is on my side. If you have
counter evidence, offer it.
>Also this says nothing about art.
I said something about art, whereas till I said it, art was
void in the conversation which I think is a glaring mistake
which is why I said it. If you have something to say about art,
say it, otherwise you don't have a dog in this fight.
dpark wrote 11 hours 2 min ago:
> you have absolutely no reason to believe they thought
anything different than we do today
People donât believe this today. What are you talking
about? Do you think most people today are hunting animals to
eat their raw hearts to gain their power at certain times of
the month?
> If you have counter evidence, offer it.
Iâm not the one claiming deep insight into the beliefs of
prehistoric peoples. Burden of proof is on you.
> I said something about art
You really didnât. You said nothing meaningful about art
except to substitute it for the word picture. And then the
rest of your replies have also had nothing to do with art.
_jayhack_ wrote 17 hours 1 min ago:
Great article. For another fantastic explainer on optics, see
3Blue1Brown's video on refraction:
HTML [1]: https://www.youtube.com/watch?v=KTzGBJPuJwM
stared wrote 17 hours 33 min ago:
I am amazed by people like Bartosz Ciechanowski and Andrey Karpathy.
What would be a lifetime side project for other smart and curious
people, they seem to release every quarter. How do they do it?
Most people who are smart and creative are nowhere near as productive.
And most people who are extremely productive don't get sidetracked by
side projects.
i_am_a_peasant wrote 5 hours 4 min ago:
tbh i think they just donât procrastinate and do stuff
ChrisArchitect wrote 17 hours 40 min ago:
(2020)
Some discussion then:
HTML [1]: https://news.ycombinator.com/item?id=25357315
dang wrote 18 hours 46 min ago:
One past thread (only?) - others?
Cameras and Lenses - [1] - Dec 2020 (213 comments)
HTML [1]: https://news.ycombinator.com/item?id=25357315
andyfilms1 wrote 18 hours 51 min ago:
Doesn't seem to work in Firefox. :(
fsckboy wrote 16 hours 43 min ago:
I use firefox with javascript mostly off (UMatrix) but when I turned
it on for fonts.googleapis.com the site and sliders all seem to
worke. then I turned it on for gstatic.com fonts.gstatic.com , and
not sure if that changed anything else. I'm on linux desktop
cfraenkel wrote 17 hours 53 min ago:
Also works in Firefox (144.0.2) / MacOS (10.15)
compiler-guy wrote 17 hours 58 min ago:
Working fine on Firefox for IOS.
mcdonje wrote 18 hours 24 min ago:
Works fine for me with Firefox on Debian. Are you sure you don't have
an extension breaking it?
uhoh-itsmaciek wrote 18 hours 38 min ago:
FF on Android seems to work fine here. What problem are you seeing?
behnamoh wrote 18 hours 52 min ago:
Can we donate to creative individuals like the OP so they keep making
amazing stuff? This is the kind of output LLMs will not be able to
produce any time soon.
sho_hn wrote 17 hours 1 min ago:
"Make a Bartosz-style website about $topic" seems like a fun
benchmark idea. Maybe more so than pelicans on bicycles.
To be honest, though, this seems like ideal content for an LLM to
produce. It's basically fact regurgitation.
dpark wrote 13 hours 48 min ago:
> It's basically fact regurgitation.
This page wasnât a regurgitation of facts. It was filled with
custom interactive applets that let you explore the effects of
physical changes. The core value proposition here is not the facts
but the ability to explore and intuit the physics.
sho_hn wrote 13 hours 13 min ago:
I do understand the contention is that an LLM would be less
thoughtful in editorializing which bits to make interactive,
reasoning about the progression in understanding and delight by
the user.
I'm not so sure it's that far out of reach, though. From what
I've seen the reasoning models do, they're not too far away from
being able to run a strategy of figuring out interesting
increments of a problem, parameterizing them, making an
interactive scene for those parameters, ... it feels within
reach.
dpark wrote 8 hours 50 min ago:
I said nothing about LLMs. I said this page was not simply
regurgitation of facts.
I personally doubt LLMs are close to producing anything like
this, but that wasnât the point. You indicated that this
should be easy for an LLM because itâs just a fact dump.
Regardless of whether some future LLM can generate something
like this, itâs much more complicated and interesting than a
simple fact dump.
macintux wrote 18 hours 41 min ago:
He has a Patreon:
HTML [1]: https://www.patreon.com/ciechanowski
Y_Y wrote 18 hours 54 min ago:
Amazing as usual.
I am always on the lookout for the classic sin of making it look like
electromagnetic waves wiggle in space like a snake. I know it's
convenient to glue the tangent space to the underlying physical space,
but I think it confuses students.
To be clear: the amplitude of the electric and magnetic fields (and
hence their components in each direction) oscillate in space/time. Any
particular wave though should travel in a straight line (usual caveats
apply). Of course you may incidentally also get e.g. sinusoidal
variations in intesity perpendicular to the wavevector, but that will
be because of the overall beam characteristics.
I don't mean to say I know a better way to show this, and I am aware of
many complicating factors. I just think lots of people (my former
students and self included) can come away with a wrong idea about how
these waves work.
mal10c wrote 14 hours 23 min ago:
I agree with your thought process. Factoring in antenna type and
reflections also causes difficulties when explaining concepts like
super position. The sinusoid is a good illustration of what a given
receiver might detect at some location (X,Y,Z). A more accurate way
to show that may be a light source fading on and off to match some
frequency (below THz). Then factoring in the speed of light, at time
zero, the light will be off, at some arbitrary time 1, the light will
be illuminated at 0.25 (scale goes up to 1 here). The light energy
peak at time 1 is at the light. Then at time 2, the light goes up to
0.5. That means that the 0.25 light is now 1 unit away from the light
while the 0.5 is at the light. Step to time 3 and the light goes up
to 0.75, meaning 1 unit from the light, the light is at 0.5 and 2
units from the light, the light is dimmer at 0.25. This repeats with
the light hitting 1.0 then falling back to 0.75, then 0.5, etc. The
movement of light is key and I think that's what is often either
misunderstood or just not considered enough.
Fiveplus wrote 18 hours 59 min ago:
Every time I come across one of Bartosz posts, I drop everything to
read it. And I learn so much.
The way he builds up the mental model from a simple photon bucket to a
pinhole and finally to a lens system is just incredible.
I particularly loved the section on the circle of confusion. I've read
dozens of explanations on depth of field, but being able to
interactively drag the aperture slider and see exactly how the cone of
light narrows and the blur reduces makes it click in a way that static
text never could. This really should be the standard for digital
textbooks.
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