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NASA’s Webb takes star-filled portrait of Pillars of Creation

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Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#111

Post by nullc »

edvards wrote: post #95
nuccy wrote: post #39

Earlier quoted context omitted.

Webb observes "much further" into the IR [1]. 1. https://www.nasa.gov/sites/default/files/thumbnails/image/hu... (this image is from [2]) 2. https://www.nasa.gov/content/goddard/hubble-vs-webb-on-the-s...

Does this mean what Hubble sees is actually closer to what I'd see with my own eyes than Hubble, or Hubble's version is closer?

Hubble can take images similar to what you see, but the famous pillars of creation image is not an example of that.

That in image in "Hubble pallet" or SHO. It's an image where the colors come from three extremely narrow spectral bands that have better contrast in astronomical images because they show ionized gasses with less noise from dust reflected blackblody light.

Red=sulphur line, Green=Hydrogen line Blue=oxygen line.

The oxygen line appear blue-green to the human eye, and the Hydrogen alpha line is a dim far red color that the eye isn't very sensitive to, the sulphur line is even further towards the infrared, barely visible at all.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#112

Post by gynln »

OscarCunningham wrote: post #23

Is there a way to get rid of the six diffusion spikes in images from James Webb? Deconvolution or something? I guess it would have some cost in terms of resolution, but I think it would be worth it for these sorts of publicity images.

What causes these spikes? I see there are also smaller ones pointing up and down too. I don't understand why any of these are there or pointing in those directions.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#113

Post by ajkjk »

alex_young wrote: post #64
ajkjk wrote: post #48

Would it be possible for them to algorithmically remove the lens artifacts? I suppose just "anything with hexagonal symmetry gets deleted". They're kinda pretty but it's sad to think that this isn't what it would actually look like if you had really good infrared eyes.

If you removed them wouldn't you just see black areas where they were?

Dunno. I'm guessing that you could remove them and see stars underneath them, because, after all, other parts of the telescope can see that patch of sky (the arms don't _entirely_ occlude it.. just from some angles). But I don't really know what I'm talking about.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#114

Post by tantalor »

ajkjk wrote: post #48

Would it be possible for them to algorithmically remove the lens artifacts? I suppose just "anything with hexagonal symmetry gets deleted". They're kinda pretty but it's sad to think that this isn't what it would actually look like if you had really good infrared eyes.

Rotate the camera and bit and take another photo?

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#115

Post by kadoban »

jallen_dot_dev wrote: post #91
vecter wrote: post #75

Earlier quoted context omitted.

They're not talking about the stars, but the hexagonal spikes sticking out of the stars. Those are artifacts of the hexagonal lenses that the telescope uses.

I think you're both right to a degree? They are lens artifacts and we can't just remove them because we don't have the data of what's behind the spikes, as that is what the sensor can see. We'd be filling them in with black or our best guess based on neighboring pixels, either way it wouldn't be what one would "really" see. Unless we composited images from another source, then that'd come closer to accurate.

That seems right. For popular consumption it'd probably be nice to have a black-filled version or something, whatever is least visually off-putting, but for science that seems much, much worse.

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#116

Post by rootw0rm »

dvasdekis wrote: post #110

I compressed the full PNG via Guetzli (Google's high-quality jpg compressor) which took a couple of hours (now 15MB at 84% quality), so here it is: https://github.com/dvasdekis/images/raw/master/pillars.jpg and https://mega.nz/file/BTdWSb6b#NHK9lAtGMIr1UxabLiC174ZvJWo7KS... and https://www.mediafire.com/file/n0qjxogsp203z0w/pillars.jpg/f... The original crashed Windows when set as desktop background, but this one wor…

Gorgeous, thank you for sharing

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#117

Post by Nition »

itishappy wrote: post #74
mwidell wrote: post #41

James Webb telescope is great and all, but I have to say I think the older image is more stunning and more aesthetically pleasing. Cleaner, simpler, nicer colors, more mysterious looking.

100% agree, but of course that's not the point. Webb's purpose is scientific measurements, not cool looking images. (Though wallpapers are a nice bonus!) When it comes to aesthetically pleasing images, I'm consistently blown away by the composite images combining Webb with other devices like Chandra. https://chandra.si.edu/photo/2022/chandrawebb/

I don't disagree with you exactly, but Webb is making some attempt at being aesthetically pleasing with these images and that work does seem to take them further from the Hubble look.

There was an article about the older Cosmic Cliffs image the other day which showed some in-progress images.[0]

Compare the final image after all editing: https://i.imgur.com/htJ25jw.jpg

With this version that's a pure stacking of colour layers: https://i.imgur.com/S1wkruc.jpg

The second one definitely has a more old-school 1990s Hubble look (and I kinda wish they'd release that version in high res).

[0] https://www.thestar.com/news/canada/2022/10/16/james-webb-te...

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#119

Post by jcpst »

ars wrote: post #19

When I go outside I can barely see any stars, unlike my ancestors who saw a sky utterly filled with stars. Then I go on my computer and I can see more stars, with more details, than my ancestors even imagined. I can't decide if it's a worthwhile tradeoff.

Maybe take a look at the International Dark Sky Places Program interactive map:

https://www.darksky.org/our-work/conservation/idsp/finder/

Re: NASA’s Webb takes star-filled portrait of Pillars of Creation

#120

Post by dylan604 »

nuccy wrote: post #28
technonerd wrote: post #27

Earlier quoted context omitted.

Handy Dandy Slider action between the two! https://esawebb.org/images/comparisons/weic2216/

Technically the comparison is not totally fair, that Hubble image was taken in visible light, while Webb's in infrared. Dust blocks visible light stronger, so background stars are effectively hidden from Hubble, but not from Webb. Here [1] you can see same field in visible and close infrared taken by Hubble. Webb of course shines in all the fine details and faint stars number. [1] https://cdn.spacetelescope.org/archi…

Fair? This is exactly why they are not the same type of telescope only Biggie Sized. Seeing these comparisons is the point. "Here's visible light, and now here's what's hiding behind the visible dust" should be the tag to everyone of these kinds of comparisons
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