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

webbtelescope.org

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

#131

Post by DiogenesKynikos »

whiteboardr wrote: post #93
roywiggins wrote: post #85

Earlier quoted context omitted.

Webb's primary camera is infrared, so there is by necessity a choice to be made with how to present the data for humans who can't see in infrared.

I am aware. (And have been eagerly waiting for this moment for ages) It just seems “unscientific” to just use Photoshop and above all curious about the set of rules and algorithms, that enables them to decide which hue to pick for which region, levels, etc.

Any real science will be done on the raw images, not on the color composites released for the public.

These color composite images really show off how awesome JWST is. They're meant for the public to enjoy (astronomers enjoy them too).

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

#132

Post by [deleted] »

ceejayoz wrote: post #75
mike10921 wrote: post #68

Earlier quoted context omitted.

Of course, I get it, but we are allowed to admit that to the average person so far it looks like more of the same.

I'm honestly not sure how you someone can look at those two photos side-by-side and think they're the same. Hubble's is like slapping a 360p cam rip on a 4k TV.

[deleted]

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

#133

Post by dmead »

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…

amateur astronomer here. (https://www.instagram.com/mead_observatory/)

1. photoshop is really good at composing different (spectral) layers together. There is alternatives to this like pixinight that are more geared toward deep sky astronomy work but I'm sure it's easier to hire people that can just take a Photoshop class.

there are many layers/masks involved for different filters. the filters accept or reject certain wavelengths of light and may be designed for specific elements on the periodic table. people often talk about hydrogen filters or oxygen filters, sulfer filters etc. the color distinction you see is actually indicating elemental composition much of the time. I'm not sure what filters webb is using.

2. modern telescopes clean up their images by taking a "master dark frame" that is a stacked frame of many frames taken with the lens cap on. The goal there is to compute the noise profile of the sensor. I'm sure before launch the darks for the sensors were determined and are at the ready to correct and calibrate images coming from the telescope. think of it as applying a bespoke noise filter for that sensor. It's a fast process to apply it, but not to generate it. If they really make the raws available I'm sure we'll see more noise there.

3. the touch up you see them doing is the removal of a hot pixel which survived the calibration process with the dark frame. no doubt on space telescopes they still get errant hot pixel of some kind of particle or cosmic ray they don't want makes it to the sensor and flips a bit (and is therefore not account for in the master dark). happens all the time. they're probably keeping a map of where they're getting hot pixels.

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

#134

Post by samstave »

chaps wrote: post #64

Direct links -- Stephan's Quintet (NIRCam and MIRI Composite Image): https://stsci-opo.org/STScI-01G7DB1FHPMJCCY59CQGZC1YJQ.png Southern Ring Nebula (NIRCam and MIRI Images Side by Side): https://stsci-opo.org/STScI-01G79R28V7S4AXDN8NG5QCPGE3.png “Cosmic Cliffs” in the Carina Nebula (NIRCam Image): https://stsci-opo.org/STScI-01G7ETPF7DVBJAC42JR5N6EQRH.png Webb's First Deep Field (NIRCam Image): https://stsci-opo.org…

May anyone please ELI5 how to interpret the WASP-96 water spectrum graph above?

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

#135

Post by vishnugupta »

chaps wrote: post #64

Direct links -- Stephan's Quintet (NIRCam and MIRI Composite Image): https://stsci-opo.org/STScI-01G7DB1FHPMJCCY59CQGZC1YJQ.png Southern Ring Nebula (NIRCam and MIRI Images Side by Side): https://stsci-opo.org/STScI-01G79R28V7S4AXDN8NG5QCPGE3.png “Cosmic Cliffs” in the Carina Nebula (NIRCam Image): https://stsci-opo.org/STScI-01G7ETPF7DVBJAC42JR5N6EQRH.png Webb's First Deep Field (NIRCam Image): https://stsci-opo.org…

If it helps others like me, I found it easier to download the images through wget and then open the local file through browser.

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

#136

Post by ricardobeat »

jacquesm wrote: post #99
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…

The difference between 'actual science' and 'some touched up version of objects in our universe' is smaller than you might think: no matter how good your eyes, if there was no frequency shift involved you would not be able to perceive the image, other than as an array of numbers. To facilitate your consumption of the data it has to be frequency shifted and the easiest way to do this is to map the IR intensity to a ra…

What would these look like, if you could point a ground telescope at the exact same spot? How much light is in the visible spectrum?

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

#137

Post by whiteboardr »

jacquesm wrote: post #99
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…

The difference between 'actual science' and 'some touched up version of objects in our universe' is smaller than you might think: no matter how good your eyes, if there was no frequency shift involved you would not be able to perceive the image, other than as an array of numbers. To facilitate your consumption of the data it has to be frequency shifted and the easiest way to do this is to map the IR intensity to a ra…

Thanks, but how is the sausage made then?

Guess, that’s my main question.

I get that the aquired data needs to be transformed in a way so we get an image that depicts a reality we can visually process.

I honestly thought there’s some tools in Nasa’s imaging group that, based on scientific rules, pumps out an image that is correct - seeing Photoshop in use left me wonder…

I get that the investment needs to be “sold” too, would be sad though if we reached fashion-ad conduct for science…

And don’t get me wrong: I am in awe and more than happy this thing finally gets put to use.

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

#138

Post by yread »

mrandish wrote: post #108
chaps wrote: post #64

Direct links -- Stephan's Quintet (NIRCam and MIRI Composite Image): https://stsci-opo.org/STScI-01G7DB1FHPMJCCY59CQGZC1YJQ.png Southern Ring Nebula (NIRCam and MIRI Images Side by Side): https://stsci-opo.org/STScI-01G79R28V7S4AXDN8NG5QCPGE3.png “Cosmic Cliffs” in the Carina Nebula (NIRCam Image): https://stsci-opo.org/STScI-01G7ETPF7DVBJAC42JR5N6EQRH.png Webb's First Deep Field (NIRCam Image): https://stsci-opo.org…

Thanks for posting these links! It was frustrating that the main NASA PR pages linked photos that were 1280x720. I guess that's to protect their bandwidth costs since much of the general public is probably viewing on mobile anyway and higher res would not only be slower but wasted bits. I just wish NASA had provided a link at the bottom of their low-res image pages to intermediate sized images (~4k) for desktop viewi…

you can also download full res (even uncompressed) images from ESA site (they developed two of the IR instruments)

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

#139

Post by samstave »

palmtree3000 wrote: post #107
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.

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 lensing, simply based on distance from the sensor"

?

I wonder if a more precise version(s) of the hex lenses could be made such that they can 'normal-ize' on a much more refined basis.

I know that each JWT is already capable of mico-flexes to each cell... but if we can develope an even further refinement (Moores law on the JWTs hex lenses resolution) we will be able to make thousands of images with varying the the normalization to each receiving area and comparing image quality.

Also, I am sure there are folks who know the reflective characteristics of photons from each wavelength that would allow for orientations for each wavelength.

--

Do ALL 'light' wavelengths, particles bounce off the reflector materials in the same way? - meaning do infra waves/photons bounce in the exact same way as some other wavelength with the exact same orientation of the sensor?

---

Do they do any 'anti-gravitational-lensing' correction calcs to 'anti-bend' a photons path to us to 're-normalize' the path that we should have seen?

Whats the current science behind such?

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

#140

Post by empyrrhicist »

vishnugupta wrote: post #127
whiteboardr wrote: post #93

Earlier quoted context omitted.

I am aware. (And have been eagerly waiting for this moment for ages) It just seems “unscientific” to just use Photoshop and above all curious about the set of rules and algorithms, that enables them to decide which hue to pick for which region, levels, etc.

The person seen photoshopping very briefly talked about how he picks different colours for different region/light-frequency. But yes, more details will definitely be helpful. Also I guess they could open-source the untouched photos for other artists and photoshop experts to play around?

They aren't "untouched photos" in any traditional sense, but rather raw data. To visualize astronomical phenomena always requires processing/compositing. For that matter, traditional cameras on earth automate many of the same tasks being done here in Photoshop via debayering.
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