Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

James Webb first images – complete set of high resolution shots now live

webbtelescope.org

Post reply on HN
Print view View original

321–330 of 410 posts

Re: James Webb first images – complete set of high resolution shots now live

#321

Post by jacquesm »

s1artibartfast wrote: post #317
TheOtherHobbes wrote: post #276

Earlier quoted context omitted.

There is no "in real life." The size, sensitivity, and spectral response of human eyes is a response to the radiation conditions on Earth, as enhanced by evolution. If the Sun had been redder or bluer and your eyes were the size of your head or much smaller, everything would look very different. The Webb images are infrared so "in real life" you'd never see them as shown here. You'd see whatever was visible in optica…

You are obviously missing the point. They want to know what it would look like to a human observer.

It's the wrong question to ask because a 'human observer' would see absolutely nothing. The age of the objects you are looking at is such that you are looking into the past not at something the is still there in the present, so if we were to transport you there you would not recognize the various objects in visible light at all, too much time has passed.

At this level 'distance' = 'time'.

Re: James Webb first images – complete set of high resolution shots now live

#322

Post by t9999999999999 »

bcherry wrote: post #222
rootusrootus wrote: post #104

Earlier quoted context omitted.

Thanks for the direct links! > Webb's First Deep Field (NIRCam Image) Is this image distorted in any way at all? It feels like the galaxies are somehow oriented around a center spot. Not all of them, but enough to give the image a distorted feeling. Probably it's just my mind pattern matching against something that doesn't really exist.

Something missing from this discussion that's worth pointing out: This image shows profound "gravitational lensing", which you know. But what you might not know is that is precisely _why_ they chose to photograph it. This galaxy cluster (SMACS 0723) may be the most well known and powerful gravitational lens we have observed. The galaxies shown distorted around the edges are actually behind the lens, but are magnified…

The elongated double lensed galaxy to the right of centre shows lots of point sources. These look like globular clusters or maybe satellite galaxies (maybe these are the same thing in the early universe?).

Re: James Webb first images – complete set of high resolution shots now live

#323

Post by [deleted] »

wthomp wrote: post #250
april_22 wrote: post #184

Earlier quoted context omitted.

Which makes me wonder how all these galaxies and nebulas would look like in real life. Would they look similar to how they colored it? Are those images maybe potraying a completely wrong reality?

If you were to fly into these nebula in some kind of spaceship they wouldn't be any brighter than they appear in the night sky from Earth. They would just look way way bigger. The frustrating thing is that our eyes start to respond differently to colours when the light is really really faint. So we would probably perceive them as a grayish green haze. If the image was brightened artificiallythen we would see it as mo…

[deleted]

Re: James Webb first images – complete set of high resolution shots now live

#324

Post by samstave »

samstave wrote: post #139
palmtree3000 wrote: post #107

Earlier quoted context omitted.

Gravitational lensing. From the description[0]: Other features include the prominent arcs in this field. The powerful gravitational field of a galaxy cluster can bend the light rays from more distant galaxies behind it, just as a magnifying glass bends and warps images. Stars are also captured with prominent diffraction spikes, as they appear brighter at shorter wavelengths. [0] https://webbtelescope.org/contents/new…

So, would that mean that the gravitational lensing over how-ever-many-light-years is ALSO coupled with the convex/cave aspect of the pico-adjusting of the JWT 'lens' such that even our JWT's pico-adjustments affect the NORMAL of the photons to the image? Can this be adjusted for? Wouldnt the pico-arc of the overall array affect the image output due to the distances involved such that we receive "false gravitational l…

I'm convinced we are receiving "Wobbly Photons"

Meaning that no matter waht, when we speak of gravitational lenses, we could, usting JWST account for the "wobble" of a photon, nased on the accurate knowledge of where a body was, via measuring through multiples of JSWT observations... (ideally through actually multiple JWSTs, in differnt locations)

The idea being that if we can triangulate a more precice location between earth [A] and galaxy [N] - set of all galaxies/bodies/whatever,

We may be able to calculate the influence of gravity lens upon phont differentials based on when they came from and how far...

Ultimately making adjustments to the output of an image \based on super deep-field focus which is effectively selecting to the phtons of interest... and we can basically "carbon date" the accuracy of an image with a higher resolution?

Re: James Webb first images – complete set of high resolution shots now live

#325

Post by HedgeGriffon »

capableweb wrote: post #45
deelowe wrote: post #14

Earlier quoted context omitted.

https://petapixel.com/2022/07/11/comparing-hubble-to-james-w...

Yeah, that's not very good implementation. PetaPixel usually have good content, but using a GIF to compare these two images? Come on! You can see the compression artifacts very easily.

Umm.. not compression artifacts. GIF uses lossless LZW. Maybe color palette artifacts since GIFs are usually palettized and not true color (although with a tortured use of local color tables they can even be true color)

Re: James Webb first images – complete set of high resolution shots now live

#326

Post by jacquesm »

jcims wrote: post #268
racingmars wrote: post #221

Earlier quoted context omitted.

The image details do have the dimensions listed in a standard measure down under the "Fast Facts" section; I assume this will be included for every image release. The deep field image says it's about 2.4 arcmin across[1], Stephan's Quintet image is about 7.4 arcmin across[2], etc. [1] https://webbtelescope.org/contents/media/images/2022/035/01G... [2] https://webbtelescope.org/contents/media/images/2022/034/01G...

I know that's usually there. I'd just love to see a little map scale bar or something in EXIF. [-----------] ° [--------] ' [----------------------] " [----------------] ,," Super easy.

Nice idea, really, and very easy to implement.

Re: James Webb first images – complete set of high resolution shots now live

#327

Post by c048 »

randyrand wrote: post #295
bottled_poe wrote: post #101

Earlier quoted context omitted.

I’m confused.. why would we expect some other image processing software to be better than Photoshop - a software package which has been the top of its class for ~30 years?

Because photoshop it not open source, not verifiable, and not documented on a scientific level about how its filters behave.

Why would they worry about that? These colored images aren't used for science, they're meant for marketing.

Re: James Webb first images – complete set of high resolution shots now live

#328

Post by ashes-of-sol »

randyrand wrote: post #295
bottled_poe wrote: post #101

Earlier quoted context omitted.

I’m confused.. why would we expect some other image processing software to be better than Photoshop - a software package which has been the top of its class for ~30 years?

Because photoshop it not open source, not verifiable, and not documented on a scientific level about how its filters behave.

No post body was provided.

Re: James Webb first images – complete set of high resolution shots now live

#329

Post by MAGZine »

randyrand wrote: post #295
bottled_poe wrote: post #101

Earlier quoted context omitted.

I’m confused.. why would we expect some other image processing software to be better than Photoshop - a software package which has been the top of its class for ~30 years?

Because photoshop it not open source, not verifiable, and not documented on a scientific level about how its filters behave.

They're not doing science with photoshop. They're creating assets for consumption by the public.

Re: James Webb first images – complete set of high resolution shots now live

#330

Post by _justinfunk »

djfobbz wrote: post #275
whiteboardr wrote: post #77

Watching the livestream i was more than surprised, that color correction actually happens in Photoshop. Also, there seem to be multiple layer-masks involved for specific regions and objects. I get that you can shift and composite color, based on hue, apply filters etc, but: Photoshop? Curious if anyone can explain, that what we see is actual science or some touched up version of objects in our universe. p.s.: What st…

I was wondering the same...why not also share the boring originals that we can process through our own filters?

https://mast.stsci.edu/api/v0/index.html

Here's the API to access the boring original data.

Post reply on HN