JWST VS Hubble, with a slider comparing each telescope images superimposed. - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: July 16, 2022, 06:03:51 am
content: Webb VS Hubble, matching shots, with a slider to compare each telescope images superimposed.Go to this website.https://www.webbcompare.com/Just click the zoom on that deep-field, go full screen, use the wheel mouse to zoom to full resolution and enjoy moving the Hubble VS web slider and click-drag panning the entire grouped images around!Hubble, we appreciate all the once great work you have given us.I anxiously await whats to come with Webb as the current images have only been taken as test images over the first week of it's final calibration.

author: Gyro
author_rank: Super Contributor
timestamp: July 16, 2022, 06:24:45 pm
content: Strangely, the images give me the layman impression that if they'd turned up the brightness up on the Hubble, the images would look more similar [EDIT: Looking at SMACS 0723]. The other thing I noticed is that a few stars (or are they galaxies?) are much brighter on Hubble and 'ordinary' on the JWST [EDIT: Carina Nebula, just at the top and above the gas cloud at the middle of the image] - IR versus visible sensors?Yes there is clearly much sharper focus and much more detail in the gas clouds, stunning images.

author: tom66
author_rank: Super Contributor
timestamp: July 16, 2022, 07:56:55 pm
content: Here is the best I could get by turning up the brightness and contrast on the the Hubble image of the Southern Ring Nebula - there really is no comparison with Webb. There simply is not the detail in the Hubble image as much as you turn the gain up.One thing to realise is that Hubble has its 'spectacles' fitted which correct the mirror error (I'm not sure if these perfectly correct the error or not?) and has older sensors, which certainly have reduced dynamic range and higher noise floors compared to newer sensors.

author: tszaboo
author_rank: Super Contributor
timestamp: July 16, 2022, 08:05:53 pm
content: Someone please fire JJ Abrams, thats way to much lens flare on these newer science fiction movies.

author: BrianHG
author_rank: Super Contributor
timestamp: July 16, 2022, 08:32:08 pm
content: All the stars with lens flares are really close, IE in the Milky Way galaxy.Also, stars seen as red in Hubble show as blue in Webb. Stars which are red as some in orange in Webb are invisible to Hubble. See around my yellow arrows where I side-by-side shifted these example shots from the website:Example 1, Webb seeing through clouds:Example 2, Hubble red seen as blue in Webb, Hubble cant see Webb's orange:Example 3, Well... Which version of this galaxy looks better? Also, can you see the other galaxies behind the current galaxy?

author: BrianHG
author_rank: Super Contributor
timestamp: July 16, 2022, 08:41:41 pm
content: Quote from: tom66 on July 16, 2022, 07:56:55 pmTurn up the Gamma instead of the brightness... Like to around 1.5 or even 2...You still wont see any details, though it will look a lot brighter.

author: iMo
author_rank: Super Contributor
timestamp: July 16, 2022, 08:56:05 pm
content: The most deep space pictures taken by Hubble were with exposition times like several days, or a week, afaik.Webb did those above ones in tens of minutes. That is a huge difference.Let us wait on the pictures taken by Webb with 5 days exposition times..

author: Gyro
author_rank: Super Contributor
timestamp: July 16, 2022, 09:36:36 pm
content: Yes, a mere 12 minutes exposure for the deep field if I remember the news interview correctly.

author: Gyro
author_rank: Super Contributor
timestamp: July 16, 2022, 09:43:09 pm
content: Quote from: tom66 on July 16, 2022, 07:56:55 pmThere looks to be a small area of chromatic aberration, in the top left corner of the Hubble SMACS 0723 image. Pretty amazing that the 'spectacles' worked so well though.Edit: Even more amazing that the shuttle crew managed to do it in orbit, even if Mike Massimino had to wrench off one of the handles to do it!

author: iMo
author_rank: Super Contributor
timestamp: July 16, 2022, 10:21:38 pm
content: One of the Webb's mirrors was hit by a dust particle, but they were able to compensate the error, they wrote..Hopefully a larger damage up there could be easily repaired by Elon's steel rocket carried his Zeus dog

author: BrianHG
author_rank: Super Contributor
timestamp: July 17, 2022, 04:21:09 am
content: Where to get Webb's source data, filter by filter and how to generate your own images:No JPEGs, no noise removal, or color scheme by NASA.Seek to 19:35 and watch this guy cycle through the different color filters of the same nebula. You will see one where the nebula's gas has disappear and only the stars are visible. It's like Webb has X-ray vision mode.

author: hamster_nz
author_rank: Super Contributor
timestamp: July 17, 2022, 07:45:02 am
content: Quote from: tszaboo on July 16, 2022, 08:05:53 pmPage 23 ofhttps://www.stsci.edu/files/live/sites/www/files/home/jwst/documentation/technical-documents/%5C_documents/JWST-STScI-001157.pdfwould help him get it right... (details the origins of the defraction spikes)

author: BrianHG
author_rank: Super Contributor
timestamp: July 18, 2022, 08:59:48 pm
content: Webb test photos which were not publicly released for some reason: (I bet we are smart enough here to know why...)

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: July 18, 2022, 09:26:01 pm
content: Quote from: BrianHG on July 16, 2022, 08:32:08 pmWhat you call lens flare is actually diffraction spikes. The following explains why the diffraction pattern around bright starts looks the way it does.

author: negativ3
author_rank: Regular Contributor
timestamp: July 18, 2022, 09:30:25 pm
content: Yea, not bad, my dads DSLR from twenty years ago had ONLY eight megapixels...The cosmos is utterly beautiful and flabbergasting.

author: BrianHG
author_rank: Super Contributor
timestamp: July 23, 2022, 06:48:20 am
content: JWST captures Jupiter's rings:

author: BrianHG
author_rank: Super Contributor
timestamp: August 04, 2022, 08:29:35 pm
content: Webb's latest new images, high res: (It takes a few clicks to zoom all the way in...)https://www.flickr.com/photos/nasawebbtelescope/albums/72177720301006030/with/52259483705/Webb's first set of images, high res:https://www.flickr.com/photos/nasawebbtelescope/albums/72177720300469752

author: BrianHG
author_rank: Super Contributor
timestamp: August 04, 2022, 10:39:41 pm
content: Quote from: Sal Ammoniac on July 18, 2022, 09:26:01 pmI wonder if Webb were to take 2 identical exposures, one slightly rotated from the other. It might be possible to negate the angle differences of the diffraction-spikes in the 2 images.

author: hamster_nz
author_rank: Super Contributor
timestamp: August 05, 2022, 01:54:09 am
content: Quote from: BrianHG on August 04, 2022, 10:39:41 pmIt is possible, but to do a rotation you would have to rotate the whole JWST structure. That would most likely not be a trivial exercise, given the constraints it has to operate under - heat shield to face the sun, antennas pointing to the Earth , need to minimizing vibrations (from reaction wheels), and the current load of propellent is all it will ever have - once that is gone the mission is over.

author: Peter_O
author_rank: Frequent Contributor
timestamp: August 10, 2022, 08:37:26 am
content: If I understand NASA right, JW is new in focussing on the infrared.So there is a lot more nwq information gained, that might not be transferable into visible pictures.