https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html
Not sure.
On Wednesday, March 16, 2022 at 7:47:52 PM UTC-7, RichA wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html
Not sure.
8th mag star can show up in my binocular, I think?
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html
Not sure.
On Wednesday, March 16, 2022 at 7:47:52 PM UTC-7, RichA wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html
Not sure.
8th mag star can show up in my binocular, I think?
On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html
Not sure.2MASS J17554042+6551277
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.
On Thursday, 17 March 2022 at 01:12:43 UTC-4, Chris L Peterson wrote:
On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html
Not sure.2MASS J17554042+6551277
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.Impressive! I wonder why they used a red filter? The mentioned something about it but didn't go into detail.
On Thursday, 17 March 2022 at 01:12:43 UTC-4, Chris L Peterson wrote:
On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html >>>2MASS J17554042+6551277
Not sure.
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.
Impressive! I wonder why they used a red filter? The mentioned something about it but didn't go into detail.
On 18/03/2022 01:05, RichA wrote:
On Thursday, 17 March 2022 at 01:12:43 UTC-4, Chris L Peterson wrote:
On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html >>>>2MASS J17554042+6551277
Not sure.
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.
Impressive! I wonder why they used a red filter? The mentioned something about it but didn't go into detail.
It is just one of many possible false colour palettes they could have
mapped the greyscale intensity image onto usually called "thermal" or >something like that. It preserves (or should preserve) luminosity so
that it will look OK on a monochrome display.
It is essentially dim red-red-dim orange-orange-yellow-white. Better
than greyscale for showing up faint details but by no means the best!
The other common one that preserves monochrome luminosity goes something
like this (with carefully chosen RBG coefficients).
dim blue-blue-purple-cyan-green-magenta-pink-white
This one:
https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/
I prefer ones that make better use of the full 3D RGB space. There are a >couple of others that preserve luminosity and use more of the colour
cube. Rainbow is currently popular at the VLA eg. Figs 1&2 here
https://arxiv.org/pdf/1107.2511.pdf
Peano-Koch twisted is my favourite brutal false colour palette for high >dynamic range images. It goes through all of the single colours and
pairwise combinations tracing along the edges of the colour cube in
sequence. Starting at black along the blue edge and ending at white.
(it doesn't preserve monotonic luminosity)
ie
black-blue-cyan-green-yellow-red-magenta-white
It is very good for seeing faint detail provided that there isn't too
much noise (even then it often works OK but looks very messy).
A series of colour coded ramps is also useful for visualising incredibly
high dynamic range almost noise free data.
I have a selection of common false colour palettes online here:
https://nezumidemon.co.uk/consult/excel/image.html
The only common ones missing is the more recent IronBow and Arctic which
has been popularised by thermal imaging cameras.
https://www.flir.co.uk/discover/industrial/picking-a-thermal-color-palette/
On Fri, 18 Mar 2022 09:37:41 +0000, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:
On 18/03/2022 01:05, RichA wrote:
On Thursday, 17 March 2022 at 01:12:43 UTC-4, Chris L Peterson wrote:
On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html2MASS J17554042+6551277
Not sure.
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.
Impressive! I wonder why they used a red filter? The mentioned something about it but didn't go into detail.
It is just one of many possible false colour palettes they could have >mapped the greyscale intensity image onto usually called "thermal" or >something like that. It preserves (or should preserve) luminosity so
that it will look OK on a monochrome display.
It is essentially dim red-red-dim orange-orange-yellow-white. Better
than greyscale for showing up faint details but by no means the best!
The other common one that preserves monochrome luminosity goes something >like this (with carefully chosen RBG coefficients).
dim blue-blue-purple-cyan-green-magenta-pink-white
This one:
https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/
I prefer ones that make better use of the full 3D RGB space. There are a >couple of others that preserve luminosity and use more of the colour
cube. Rainbow is currently popular at the VLA eg. Figs 1&2 here
https://arxiv.org/pdf/1107.2511.pdf
Peano-Koch twisted is my favourite brutal false colour palette for high >dynamic range images. It goes through all of the single colours and >pairwise combinations tracing along the edges of the colour cube in >sequence. Starting at black along the blue edge and ending at white.
(it doesn't preserve monotonic luminosity)
ie
black-blue-cyan-green-yellow-red-magenta-white
It is very good for seeing faint detail provided that there isn't too
much noise (even then it often works OK but looks very messy).
A series of colour coded ramps is also useful for visualising incredibly >high dynamic range almost noise free data.
I have a selection of common false colour palettes online here:
https://nezumidemon.co.uk/consult/excel/image.html
The only common ones missing is the more recent IronBow and Arctic which >has been popularised by thermal imaging cameras.
https://www.flir.co.uk/discover/industrial/picking-a-thermal-color-palette/ Yes, but... the details of the image say that it was actually imagedthrough a red filter to improve contrast, which is entirely separate
from the color mapping used to display it.
BTW, this is not a "false color palette", it is a "pseudocolor
palette". False color mapping applies to multiple channel images. This
is a single channel, where a grayscale is mapped to some color
palette. That's pseudocolor mapping.
On Friday, 18 March 2022 at 09:53:15 UTC-4, Chris L Peterson wrote:
On Fri, 18 Mar 2022 09:37:41 +0000, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:
On 18/03/2022 01:05, RichA wrote:through a red filter to improve contrast, which is entirely separate
On Thursday, 17 March 2022 at 01:12:43 UTC-4, Chris L Peterson wrote:
On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html2MASS J17554042+6551277
Not sure.
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.
Impressive! I wonder why they used a red filter? The mentioned something about it but didn't go into detail.
It is just one of many possible false colour palettes they could have
mapped the greyscale intensity image onto usually called "thermal" or
something like that. It preserves (or should preserve) luminosity so
that it will look OK on a monochrome display.
It is essentially dim red-red-dim orange-orange-yellow-white. Better
than greyscale for showing up faint details but by no means the best!
The other common one that preserves monochrome luminosity goes something
like this (with carefully chosen RBG coefficients).
dim blue-blue-purple-cyan-green-magenta-pink-white
This one:
https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/
I prefer ones that make better use of the full 3D RGB space. There are a
couple of others that preserve luminosity and use more of the colour
cube. Rainbow is currently popular at the VLA eg. Figs 1&2 here
https://arxiv.org/pdf/1107.2511.pdf
Peano-Koch twisted is my favourite brutal false colour palette for high
dynamic range images. It goes through all of the single colours and
pairwise combinations tracing along the edges of the colour cube in
sequence. Starting at black along the blue edge and ending at white.
(it doesn't preserve monotonic luminosity)
ie
black-blue-cyan-green-yellow-red-magenta-white
It is very good for seeing faint detail provided that there isn't too
much noise (even then it often works OK but looks very messy).
A series of colour coded ramps is also useful for visualising incredibly
high dynamic range almost noise free data.
I have a selection of common false colour palettes online here:
https://nezumidemon.co.uk/consult/excel/image.html
The only common ones missing is the more recent IronBow and Arctic which
has been popularised by thermal imaging cameras.
https://www.flir.co.uk/discover/industrial/picking-a-thermal-color-palette/ >> Yes, but... the details of the image say that it was actually imaged
from the color mapping used to display it.
BTW, this is not a "false color palette", it is a "pseudocolor
palette". False color mapping applies to multiple channel images. This
is a single channel, where a grayscale is mapped to some color
palette. That's pseudocolor mapping.
Likely all you will see coming from that scope as the public won't understand shades of grey. The Hubble it ain't.
On Fri, 18 Mar 2022 15:53:04 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
On Friday, 18 March 2022 at 09:53:15 UTC-4, Chris L Peterson wrote:
On Fri, 18 Mar 2022 09:37:41 +0000, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:
On 18/03/2022 01:05, RichA wrote:Yes, but... the details of the image say that it was actually imaged
On Thursday, 17 March 2022 at 01:12:43 UTC-4, Chris L Peterson wrote: >> >>> On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com> >> >>> wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html2MASS J17554042+6551277
Not sure.
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.
Impressive! I wonder why they used a red filter? The mentioned something about it but didn't go into detail.
It is just one of many possible false colour palettes they could have
mapped the greyscale intensity image onto usually called "thermal" or
something like that. It preserves (or should preserve) luminosity so
that it will look OK on a monochrome display.
It is essentially dim red-red-dim orange-orange-yellow-white. Better
than greyscale for showing up faint details but by no means the best!
The other common one that preserves monochrome luminosity goes something >> >like this (with carefully chosen RBG coefficients).
dim blue-blue-purple-cyan-green-magenta-pink-white
This one:
https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/
I prefer ones that make better use of the full 3D RGB space. There are a >> >couple of others that preserve luminosity and use more of the colour
cube. Rainbow is currently popular at the VLA eg. Figs 1&2 here
https://arxiv.org/pdf/1107.2511.pdf
Peano-Koch twisted is my favourite brutal false colour palette for high >> >dynamic range images. It goes through all of the single colours and
pairwise combinations tracing along the edges of the colour cube in
sequence. Starting at black along the blue edge and ending at white.
(it doesn't preserve monotonic luminosity)
ie
black-blue-cyan-green-yellow-red-magenta-white
It is very good for seeing faint detail provided that there isn't too
much noise (even then it often works OK but looks very messy).
A series of colour coded ramps is also useful for visualising incredibly >> >high dynamic range almost noise free data.
I have a selection of common false colour palettes online here:
https://nezumidemon.co.uk/consult/excel/image.html
The only common ones missing is the more recent IronBow and Arctic which >> >has been popularised by thermal imaging cameras.
https://www.flir.co.uk/discover/industrial/picking-a-thermal-color-palette/
through a red filter to improve contrast, which is entirely separate
from the color mapping used to display it.
BTW, this is not a "false color palette", it is a "pseudocolor
palette". False color mapping applies to multiple channel images. This
is a single channel, where a grayscale is mapped to some color
palette. That's pseudocolor mapping.
Likely all you will see coming from that scope as the public won't understand shades of grey. The Hubble it ain't.The JWST images through multiple filters, so the majority of its data,
like the HST, will be multiple channel and displayed using a false
color palette.
On 17/03/2022 10:18, Martin Brown wrote:
On 17/03/2022 03:08, StarDust wrote:
On Wednesday, March 16, 2022 at 7:47:52 PM UTC-7, RichA wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html >>>
Not sure.
8th mag star can show up in my binocular, I think?
Only if you have far infrared vision. The original image is online and downloadable from Flickr by following the links from
https://www.nasa.gov/content/goddard/webb-telescope-image-galleries-from-nasa/
Direct link (which might change)
https://www.flickr.com/photos/nasawebbtelescope/51942047253/
Download at original resolution to see a lot more detail than the poxy versions in the press. Native image size is 5437 x 3438 (odd size!).
Focus and phase on the left hand and particularly top side is spot on.
Lower half and right side there are stars with phase cancellationIt looks like some sort of filter glint correction algorithm that is
nulling out their central core which should be in phase (or some other weird instrumental artefact). I reckon the sharp edged pixelated black pixels in bright objects are definitely an instrumental artefact.
still a bit cack handed about how well it removes them.
If you take the image turn it into greyscale and then wind the wick up
on the dark areas by setting gamma to 3 or 4 you will see the residuals
for the rectangular grid of ghost reflected images of the main star
(much more obvious on left side). And also rectangular artefacts caused
by the sharp edges of the correction PSF.
It still works in the colour version but red background looks ugly.
The number of background galaxies with exciting shapes in the backgroundWay more small faint galaxies are visible (along with a few hot pixels).
is quite staggering. There is a rather beautiful face on spiral half on
at the bottom left with a companion almost an M51 look alike!
--
Regards,
Martin Brown
On Sunday, 20 March 2022 at 09:29:57 UTC-4, Martin Brown wrote:[snip]
On 17/03/2022 10:18, Martin Brown wrote:
Focus and phase on the left hand and particularly top side is spot on.It looks like some sort of filter glint correction algorithm that is
Lower half and right side there are stars with phase cancellation
nulling out their central core which should be in phase (or some other
weird instrumental artefact). I reckon the sharp edged pixelated black
pixels in bright objects are definitely an instrumental artefact.
still a bit cack handed about how well it removes them.
If you take the image turn it into greyscale and then wind the wick up
on the dark areas by setting gamma to 3 or 4 you will see the residuals
for the rectangular grid of ghost reflected images of the main star
(much more obvious on left side). And also rectangular artefacts caused
by the sharp edges of the correction PSF.
That's interesting. I'd have expected the sensors used to be perfect. They used to charged something like 10x as much for
that grade of sensor (CCD) over industrial or "consumer" grades. Texas Instruments once did anyway.
On Saturday, 19 March 2022 at 08:59:05 UTC-4, Chris L Peterson wrote:
On Fri, 18 Mar 2022 15:53:04 -0700 (PDT), RichA <rande...@gmail.com>
wrote:
On Friday, 18 March 2022 at 09:53:15 UTC-4, Chris L Peterson wrote:The JWST images through multiple filters, so the majority of its data,
On Fri, 18 Mar 2022 09:37:41 +0000, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:
On 18/03/2022 01:05, RichA wrote:Yes, but... the details of the image say that it was actually imaged
On Thursday, 17 March 2022 at 01:12:43 UTC-4, Chris L Peterson wrote: >> >> >>> On Wed, 16 Mar 2022 19:47:50 -0700 (PDT), RichA <rande...@gmail.com> >> >> >>> wrote:
https://phys.org/news/2022-03-space-telescope-image-star-photobombed.html2MASS J17554042+6551277
Not sure.
V mag is 11.95. Somewhat brighter in the IR.
http://simbad.cds.unistra.fr/simbad/sim-id?Ident=2MASS+J17554042%2B6551277&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id
That's 100 times dimmer than a mag 7 star.
Impressive! I wonder why they used a red filter? The mentioned something about it but didn't go into detail.
It is just one of many possible false colour palettes they could have
mapped the greyscale intensity image onto usually called "thermal" or
something like that. It preserves (or should preserve) luminosity so
that it will look OK on a monochrome display.
It is essentially dim red-red-dim orange-orange-yellow-white. Better
than greyscale for showing up faint details but by no means the best!
The other common one that preserves monochrome luminosity goes something >> >> >like this (with carefully chosen RBG coefficients).
dim blue-blue-purple-cyan-green-magenta-pink-white
This one:
https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/
I prefer ones that make better use of the full 3D RGB space. There are a >> >> >couple of others that preserve luminosity and use more of the colour
cube. Rainbow is currently popular at the VLA eg. Figs 1&2 here
https://arxiv.org/pdf/1107.2511.pdf
Peano-Koch twisted is my favourite brutal false colour palette for high >> >> >dynamic range images. It goes through all of the single colours and
pairwise combinations tracing along the edges of the colour cube in
sequence. Starting at black along the blue edge and ending at white.
(it doesn't preserve monotonic luminosity)
ie
black-blue-cyan-green-yellow-red-magenta-white
It is very good for seeing faint detail provided that there isn't too
much noise (even then it often works OK but looks very messy).
A series of colour coded ramps is also useful for visualising incredibly >> >> >high dynamic range almost noise free data.
I have a selection of common false colour palettes online here:
https://nezumidemon.co.uk/consult/excel/image.html
The only common ones missing is the more recent IronBow and Arctic which >> >> >has been popularised by thermal imaging cameras.
https://www.flir.co.uk/discover/industrial/picking-a-thermal-color-palette/
through a red filter to improve contrast, which is entirely separate
from the color mapping used to display it.
BTW, this is not a "false color palette", it is a "pseudocolor
palette". False color mapping applies to multiple channel images. This
is a single channel, where a grayscale is mapped to some color
palette. That's pseudocolor mapping.
Likely all you will see coming from that scope as the public won't understand shades of grey. The Hubble it ain't.
like the HST, will be multiple channel and displayed using a false
color palette.
Hubble colours aren't completely faked. They may be enhanced. They even use them in amateur photography now.
However, since we don't see any colour distinctions in the IR, the images from Webb will be colourized.
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