Search found 50 matches

by jfgout
Fri Nov 03, 2023 2:46 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)
Replies: 33
Views: 34902

Re: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)

The beauty of a composite won't be taken away by being truthful about how it was made. So in the end, from an ethical standpoint we all have to look at it from the intention of the imager/artist - they erroneously declared "The Moon is real, but it is artificially brightened to enhance its out...
by jfgout
Wed Nov 01, 2023 6:53 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)
Replies: 33
Views: 34902

Re: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)

One last details, and then I stop beating the dead horse: the size of the Moon changes between the different images :lol2: It has a diameter of 63 pixels on the partial phases, but it is scaled down for the annularity, otherwise it would completely cover the sun :lol2: It is even more obvious on the...
by jfgout
Wed Nov 01, 2023 4:17 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)
Replies: 33
Views: 34902

Re: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)

The geometry is not realistic, either. At the coordinates of Factory Butte, annular eclipse happens when the Sun is 30 degrees (~60 solar diameters) above the horizon, whereas this picture has the Sun barely 15 solar diamaters above. http://xjubier.free.fr/en/site_pages/solar_eclipses/ASE_2023_Goog...
by jfgout
Wed Nov 01, 2023 4:00 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)
Replies: 33
Views: 34902

Re: APOD: Annular Solar Eclipse over Utah (2023 Nov 01)

I find this part of description extremely misleading: "The Moon is real, but it is artificially brightened to enhance its outline". Reading this, one might think that the photographer just stretched the levels or used some sort of HDR technique to make the outline of the Moon visible. In r...
by jfgout
Fri Feb 17, 2023 3:29 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Comet ZTF and Mars (2023 Feb 13)
Replies: 37
Views: 10947

Re: APOD: Comet ZTF and Mars (2023 Feb 13)

I note that the author is in no hurry to answer problematics questions such as: what focal length was used for the two different images. Before this thread gets completely forgotten, I'm going to write my own "honest" version of this APOD's description: Reading back the description for thi...
by jfgout
Tue Feb 14, 2023 3:43 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Comet ZTF and Mars (2023 Feb 13)
Replies: 37
Views: 10947

Re: APOD: Comet ZTF and Mars (2023 Feb 13)

There remain few points that are really a little bit confusing at least for me. You shot the Comet-Mars conjunction from sunset 'till 22:45, local time approximately. At this time there's still a good amount of sky (Jupiter, Cetus, etc...) between them and the horizon where they'll set later one. W...
by jfgout
Tue Feb 14, 2023 2:27 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Comet ZTF and Mars (2023 Feb 13)
Replies: 37
Views: 10947

Re: APOD: Comet ZTF and Mars (2023 Feb 13)

Dear @Jfgout and @Ann, Thanks for your review even though frankly I believe you are a bit too strong in your words and frankly, especially from professionals or anyway experts, I would expect a bit less aggressive/offensive tones and more constructive words… anyway let me please try again I clearly...
by jfgout
Tue Feb 14, 2023 2:40 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Comet ZTF and Mars (2023 Feb 13)
Replies: 37
Views: 10947

Re: APOD: Comet ZTF and Mars (2023 Feb 13)

Well, what do you think? It's the same dark nebula, isn't it? And isn't it interesting that the photographer has managed to bring out this nebula? It sure isn't often that we see dark nebulas showing up in images that are meant to show us something else entirely. I'm not talking about iconic dark n...
by jfgout
Tue Jun 28, 2022 10:23 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

We are sorry to have created all this havoc, but the result of all this is that first of all 4 different rooms were used. Also, the photo is not a single photo but a composition of 10 panels, so the position of the planets may be slightly distorted. Finally, the planets were photographed a few hour...
by jfgout
Tue Jun 28, 2022 7:20 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

I certainly think there is something wrong with the image. The ratios of the distances between the planets in the image is very inconsistent with their actual positions that morning. That's problematic. I just prefer to assume it's a processing problem, as opposed to some kind of deliberate fake (n...
by jfgout
Tue Jun 28, 2022 6:29 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

How hot pixels appear depends very much on the processing and on how one-shot-color cameras handle them internally, even before we get the "raw" images out. You are reading way too much into your analysis. All you have is a JPEG image, which means the sort of halos and edges you're lookin...
by jfgout
Tue Jun 28, 2022 1:04 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

They look to me like hot pixels, not stars, and I'd expect that sort of repeating pattern. That said, I've long advocated for APOD to refuse to accept any images that don't have full processing details available. But that hasn't happened, and doesn't seem to be a priority or interest of the editors...
by jfgout
Tue Jun 28, 2022 3:12 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

It is possible that there were processing errors. I think calling it a "fake image" is extreme and not well supported. I did not make these claims lightly. No, these are not processing errors. The problem with Mercury was clearly illustrated by mars_s in some of the previous messages with...
by jfgout
Mon Jun 27, 2022 7:17 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

My assumption is that the layers cover the same FOV (or approximately so), and were taken at different exposures in order to cover the wide dynamic range of the different planets. Or perhaps a combination of exposure time and position, optimized for the targets. Perfectly acceptable, IMO. Chris, Th...
by jfgout
Mon Jun 27, 2022 4:43 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

I totally agree with jfgout. Saturn is even more off than mercury. If you look closer everything is somehow off. In the following image Venus and Jupiter are used as reference points. https://i.postimg.cc/sXjr06BP/planets-apod.jpg I tried many different projection methods, but no chance to fit the ...
by jfgout
Mon Jun 27, 2022 4:03 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

So, here's what I see with Stellarium set to Ladispoli, Italy on 6/24/2022 compared with the APOD. planet alignment on 6-24 from Ladispoli, Italy.JPG planet alignment on 6-24 from Ladispoli, Italy APOD.JPG Thank you for posting the screenshot. In case it's not obvious to everyone, you can compare t...
by jfgout
Mon Jun 27, 2022 2:31 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

How are you so certain that the image of Mercury shown in the APOD is actually a star? I didn't understand your first explanation above. Also, there's a bright object - a star? - very close to Venus and being partially eclipsed by it, that I'm not clear about either. mercury and venus.JPG You can u...
by jfgout
Mon Jun 27, 2022 1:03 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

There's nothing wrong with constructing an image like this out of stacked layers. Using stacked layers can be an acceptable method, but not the way it was done here! Maybe you are still under the impression that they simply used layers to cover a wider field of view than what camera can record (whi...
by jfgout
Mon Jun 27, 2022 2:14 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

This object surely is odd looking: object near mars.png Yes, and there are plenty such fake stars throughout the image (visible on the full resolution). Even some that are visible in the ground!!!! That's because these stars come from a completely different image that was added as a layer. Layer, l...
by jfgout
Sun Jun 26, 2022 8:54 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Planets of the Solar System (2022 Jun 25)
Replies: 46
Views: 11050

Re: APOD: Planets of the Solar System (2022 Jun 25)

As I mentioned on facebook, it is difficult to understand how this image adheres to the APOD's ethic's statement: "APOD accepts composited or digitally manipulated images, but requires them to be identified as such and to have the techniques used described in a straightforward, honest and compl...
by jfgout
Wed Apr 27, 2022 6:11 pm
Forum: The Observation Deck: Latest Sky Photography
Topic: Submissions: 2022 April
Replies: 74
Views: 108265

Re: Odd Clouds

MrRat wrote: Wed Apr 27, 2022 1:43 pm Looked at the conjunction this morning and saw the oddest clouds. Shot with a Pixel 3 in Hartford, AL, USA

PXL_20220427_102648563.NIGHT.jpg
Hello neighbor, these are contrails from the Falcon 9 crew-4 rocket launch from Cape Canaveral.

jf
by jfgout
Wed Apr 27, 2022 6:10 pm
Forum: The Observation Deck: Latest Sky Photography
Topic: Submissions: 2022 April
Replies: 74
Views: 108265

Planetary conjunction and Falcon 9 contrail

I got up early this morning to take some pictures of the planetary conjunction and I was treated with two nice surprises: 1) In addition to Jupiter, Venus, Mars, Saturn and the Moon, Neptune is (barely) visible in some images! But the real treat is that 2) The contrail from the Falcon 9 launch was s...
by jfgout
Tue Dec 28, 2021 3:45 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Comet Leonard behind JWST Launch Plume (2021 Dec 27)
Replies: 48
Views: 20527

Re: APOD: Comet Leonard behind JWST Launch Plume (2021 Dec 27)

The JWST itself ( not the Ariane ) was supposed to have its first burn at around launch time plus 12 hours (i.e., just prior to sunrise at the Thai National Observatory in Doi Inthanon National Park). Since burns are most effective near perigee (i.e., maximum velocity) presumably the JWST has almos...
by jfgout
Mon Dec 27, 2021 9:36 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Comet Leonard behind JWST Launch Plume (2021 Dec 27)
Replies: 48
Views: 20527

Re: APOD: Comet Leonard behind JWST Launch Plume (2021 Dec 27)

The JWST itself ( not the Ariane ) was supposed to have its first burn at around launch time plus 12 hours (i.e., just prior to sunrise at the Thai National Observatory in Doi Inthanon National Park). Since burns are most effective near perigee (i.e., maximum velocity) presumably the JWST has almos...
by jfgout
Mon Dec 27, 2021 5:02 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Comet Leonard behind JWST Launch Plume (2021 Dec 27)
Replies: 48
Views: 20527

Re: APOD: Comet Leonard behind JWST Launch Plume (2021 Dec 27)

The author gave more information on facebook: https://www.facebook.com/photo.php?fbid=10107696532054865&set=p.10107696532054865&type=3 Very little doubt in my mind: this is a real, single shot image. And a great one! (Unlike this one for example: https://apod.nasa.gov/apod/ap211025.html ) jf