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Cameras and Lenses

ciechanow.ski

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Re: Cameras and Lenses

#81

Post by daturkel »

dandare wrote: post #25

It may not seem interesting at first, but I am intrigued by how they managed to draw the overlapping blades of the IRIS. > In real camera lenses an adjustable aperture is often constructed from a set of overlapping blades that constitute an iris. If you naively create 6 blades and rotate them around the pivot (the tiny screw), they will never overlap EACH OTHER. One will end up at the very top, and one at the very bo…

This is interesting. I don't know much about html canvas, but it looks like this is handled in the author's custom js [0] in the line that starts with: "} else if (mode === "blades") {"

[0] https://ciechanow.ski/js/lenses.js

Re: Cameras and Lenses

#82

Post by echelon »

h_spacer wrote: post #78
echelon wrote: post #75

Earlier quoted context omitted.

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

Sorry to hear that you hold other cultures in such low regard.

Culture and gender aren't linked.

Does culture tell you if someone's gender, sexual preferences, what kind of car they drive, whether or not they're a furry, what god(s) they do or do not believe in, etc.?

Don't put people in boxes based on your limited world view.

Think about the limit. When we're uploaded to the matrix, you'll finally be able to be whatever gender you want to be without fear for the stupid stigmas of this world. You can try lots of things. You can be a man, woman, multi-gender foxperson, or a stoic agender deity. Maybe lots of things. You'll be free.

Let people be who they are.

You be who you are.

Just be happy.

Re: Cameras and Lenses

#83

Post by barrenko »

emllnd wrote: post #57
barrenko wrote: post #53

Earlier quoted context omitted.

Not sure but - as film e.g. captures actual photons from the scene, probably some kind of information is encoded through that. Bokeh is a kind of of space representation, similar to how you can basically "see" through hearing a sound stage of instruments separated properly when someone has a really good sound system, or how dogs have "5.1/7.1" sense of smell. How does one encode that I have no idea.

Look into light field photography tech. It is possible to capture a ”volume of light”, within which bokeh & more can be adjusted after the fact. Issue is the amount of data generated and complexity of tech versus getting a ”good enough for most situations” image via simpler means (regular photo). Regular + depth images (Apple LiDAR etc) with help of AI can create something vaguely similar to actual bokeh, but they’re…

Wow, thanks!

Re: Cameras and Lenses

#84

Post by _ph_ »

zokier wrote: post #48
_ph_ wrote: post #37

Earlier quoted context omitted.

You are right, this is a challenge. The wavelength of the light cannot be measured directly, only inferred by the intensity of the pixels with the different color filters. On the other side, most reproductions of photos are reproducing the original frequencies either. A computer screen has red, green and blue dots, which produce light at the corresponding wave lenghts. So if you have orange light, you have a signal o…

> The wavelength of the light cannot be measured directly, only inferred by the intensity of the pixels with the different color filters. Well, depending how you think "directly" but you can get pretty far with spectrometer, i.e. device that splits light and measures the intensity spatially to collect a spectrum. It's not impossible thought to build camera based on that principle, just need to sample the light in an…

I was talking here about the typical foto cameras. Of course you can measure the wavelength of the light with other devices like spectrometers. I was specifically talking about camera sensors which have separate filters in usually 3 colors in front of the pixels. The sensors, which are made by Sigma, formerly Foveon, use a different principle. They determine the wavelength by measuring how deep electrons are generated by the photons in the silicon. The depth depends on the wavelength of the light. However, it is more difficult to get a precise color response that way as you cannot just use predefined color-filters.

Re: Cameras and Lenses

#85

Post by filleokus »

This is so good!

I wonder if the author publishes the source code for the interactive bits somewhere (I could of course look at them from the presented JS, but still). I've been looking for a non-fan-inducing way to generate a DOF-effect, and the one in the first example is definitely good enough for my use case.

Re: Cameras and Lenses

#86

Post by throwaway98797 »

echelon wrote: post #79
kepler1 wrote: post #20

The site is the work of a guy, "him", and "his" work. We don't have to guess and say "them" and "their" work.

> 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.

Re: Cameras and Lenses

#87

Post by _def »

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 ;)

Re: Cameras and Lenses

#88

Post by _def »

giuliomagnifico wrote: post #39

The article is very good but you have to consider the existence of other filters, not only the Bayer one. And the Canon Dual Pixel AF that works a bit different than the article explains https://www.canonwatch.com/dual-pixel-af-has-become-a-canon-... (but the substance is the same)

In the article it is clearly acknowledged that there are different types. When you create a introduction like this you kind of have to limit your scope

Re: Cameras and Lenses

#89

Post by thrav »

iamacyborg wrote: post #46
lm28469 wrote: post #34

FYI there are digital sensors which aren't using bayer filters. Some are classic sensors missing the bayer filter (leica monochrome for example) other are based on different tech like Foveon sensors [0] Many people also debayer their cameras themselves, especially in astro photography [1] [0] https://en.wikipedia.org/wiki/Foveon_X3_sensor [1] https://stargazerslounge.com/topic/166334-debayering-a-dslrs...

Fuji also use what they call an X-Trans sensor. https://en.wikipedia.org/wiki/Fujifilm_X-Trans_sensor

I picked up a Fuji last Christmas, and it’s one of the best purchases I’ve made in the last decade. Their X-line takes incredible pictures, and is so approachable. If anyone has been considering more serious photography, or is having a child and wants to capture more unique shots of them, I can’t recommend them highly enough.

Re: Cameras and Lenses

#90

Post by foo_barrio »

dTal wrote: post #74
ehejsbbejsk wrote: post #38

As a hobby photographer, this is simply amazing and the most intuitive article I’ve come across. This is a must read. I am curious, however, why we still can’t digitally reproduce bokeh. Apple is getting close. I thought LiDAR would theoretically solve that and could yield indistinguishable renders compared to analog lenses. That would be a game changer in my view and why I would like to see Apple develop a full-fram…

A large lens captures information over an area, and so to a certain extent can "see around" out of focus objects. A selective blur of a fully focused scene captured from a single viewpoint (i.e. a small lens) can only approximate this effect, because it simply doesn't have access to the same information. Even with a perfect depth map, you still don't know what's behind occluded objects.

If instead of resolving points of light on the image sensor, you use a group of pixels to resolve an entire tiny image you can effectively also see around things. You end up with a picture of many small sections of the large image each at a different angle. The image on the far left of the image would see a different angle than the image on the far right. This is exactly what the Lytro camera did and it's why you can take the picture first and focus later. Of course you sacrifice overall imagine resolution quite severely:

* https://www.researchgate.net/figure/a-b-The-first-and-second...

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