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Old 09-11-2016, 08:09 PM
Sol-Skysailor (Sol)
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3D? Supermoon and any moon

Hello All,

Hope you can advise as to the feasibility of this. It’s a wondering that hasn’t been worked through rigorously but I'll take the plunge to ask. Sorry if a bit daft.

If field observers far apart on the globe but on approximately the same meridian line (or another better line) take images/videos of the moon, anytime (supermoon included, perhaps especially), would that create some useful (yielding info) or interesting (artistically) 3D data (to analyse) or images (to look at)?

If so, what 2 or more groups/societies could be contenders to work together synchronously? Do they have to have the same equipment or image spec. can be basic anough?

I realised 3D lunar views have been available and taken by probes. I mean can astrophotographers on the ground achieve this, for fun and interest? (I cannot do this myself but am interested if this can be done and whether it is of interest for some people to make it happen.)

Some calculations below. Please help check if I missed something or made mistakes –quite dreading this.

Thank you!
Sol

Given moon perigee 357000 km, apogee 406000 km, earth dia. approx. 12700 km.
To have a similar angular 3D effects to: human eyes separation 7 cm, seeing an object x metre away,
Distance between 2 locations on Earth needs to be y:
X =3 metres, y = 8330 km when moon closest, 9474 km when moon furthest,
X = 5 metres, y = 4998 when moon closest, 5684 km when moon furthest.

Example locations: Sth Afr to Finland 10254 km, Hobart Sapporo 9569 km, Adelaide Kyoto 7778 km.
And somewhere in Argentina or Chile to somewhere in Canada
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Old 09-11-2016, 08:31 PM
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Hi Sol,

That's an interesting question. In terms of trying to produce a 3D view for general consumption it would need to be in a format widely available, so nothing like stereoscopic viewers, more like 3D video on compatible TVs and monitors with those silly glasses.

So in trying to answer the question you could research the Panasonic 3D video camera/lens and use one to get a feeling for the sort of camera/subject distances which produce a reasonable 3D effect for the given (very small maybe 10-20mm lens spacing on this video camera). You could then scale up that distance between the two lenses such that a reasonable 3D effect might be expected between say the moon and clouds or perhaps the much more distant starfield from 2 widely spaced telescopes.

You would have to understand, somehow recreate the image processing of this sort of thing and apply it to two telescopes .....

Best
JA

http://www.shedworx.com/files/images...hdc-sdt750.jpg

https://www.bhphotovideo.com/images/...der_723055.jpg
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Old 09-11-2016, 11:32 PM
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Just a note; for photographic purposes, the eye 7cm separation is not the standard separation between the optical axes for various reasons, mostly to do with the fact that sterescopic 3D is an illusion and not actually how we see the world in real life. There are fixed lens hobby 3D cameras with this separation, but they typically deliver terrible, unwatchable 3D. All professional cameras have a mirror rig that allows them to vary the interaxial distance. Most shots in the movies you see are between say, 5 and 50mm interaxial, often moving during the take as the scene changes.

However, for extracting data (photogrammetry), much greater interaxials are often used.

As far as your problem goes it's about angles. Typically a 3D image (for visual use) is limited by the degree of difference between the two views once the convergence point has been set (the moon). If that didn't make sense, look at your finger in front of your face. Your eyes turn in (converge) on it. Notice how the background is different between each view? The percentage of the screen that is different is the key in any stereoscopic image. The maximum is usually 3-5% of screen width before your eyes start to bleed. In your case, because the background will be black, you can probably get away with a bit more - all that will happen is the moon will become rounder (up to a point). But given that the same side of the moon always faces us (more or less) the question is will there be enough parallax to get 3D?

Scaling it down to terrestrial measurements, it's like having a 12.7mm interaxial on an object that is 35.7cm away from the camera. So yes, yu should be able to 'see around' the edge of the moon enough to get a stereo shot. The answer suprised me, but yes, it should be possible. Keep in mind that the thing you are hoping to capture, ie the 'roundness of the moon', will be somewhat flattened by the use of very long lenses.

You could try a baseline that involves taking an image just after sunset and just before dawn and allow the rotation of the earth to give you the required distance. (slight distance in phase shouldn't be an issue over that period of time.

Or possibly you may want to try using the natural lunar librations as a means of 'seeing around the edge' of the moon (as this is what creates the 3D effect. Hope that helps.

The best effect overall will be if you can set the moon against a field of stars (best photographed separately - the real stars won't cut it in this case) because its the parallax between moon in the mid ground and the background that really brings out the 3D. Maybe throw the ISS in the foreground for more depth! :-)

Cheers and good luck!

Markus

source; Me! (I used to work as a stereographer).

Last edited by Stonius; 10-11-2016 at 11:29 AM. Reason: said 35.7mm. Meant cm
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Old 10-11-2016, 01:03 PM
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I got to thinking about my previous post. If even lunar libration would help with the 3D effect, then any two images of the moon at the same phase should work for 3D, as long as they were not taken both at the same time and place. To make sure I wasn't crazy I did a little test. I took literally the first two images google threw up that looked like they had a similar dynamic range and wouldn't require too much colour matching.

I put them in Photoshop and lined them up and Wallah! Instant roundy 3D moon!

There are two sets of pics below. One for those who can do the cross-eyed 3D viewing, and one for those who have an appropriate viewer. If you use the wrong one, the eyes will be reversed and the moon will appear to be concave, rather than convex!

Cheers

Markus
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Old 12-11-2016, 06:57 PM
Sol-Skysailor (Sol)
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Thanks, JA. Thanks, Markus.

Yes, after reading your explanation I thought hey images at libration opposites should work then. Amazing what you explained and showed. I have (had) magic eyes but my eyesight has changed unevenly so will stare at them some more.

For fun, ie the fun of an occasion like this supermoon or any moon, and maybe to make processing easier, maybe especially with time stamp?, I hope-wish-pray-plead that people a far distant apart would at the same time shoot the moon.

Including for a magnified part of the moon, at crescent limbs -or at full moon if such lighting would work. For 3D craters and rilles?

The 3D processing could be organised after, do you think? Like, the red/cyan or polarising even though producing images of images would work well?

Markus, you're heaven sent for 3D. Lucky for us you saw the questions and kindly reponded.

Cheers
Sol
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Old 13-11-2016, 08:42 AM
Sol-Skysailor (Sol)
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Markus, and others,

Please confirm that I understood your explanation and demonstration correctly.... it is possible to create a 3D video of the moon?

If people along the lines of the example locations in the first post take videos of this special supermoon, rising and setting if only for the colours from the earth atmospheric effects or for some artistic expression of the midground like the ocean or landmass added later, and at the time of any ISS or any satellite cross path, these could be processed into a 3D video?

If so, would readers please contact the people? Sorry for this question from one who does not use a twitter/FB a/c or a long range ham radio which ought to be much more effective than emails to unknown organisations.

Thank you
Sol
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Old 13-11-2016, 12:16 PM
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Quote:
Originally Posted by Sol-Skysailor View Post
Markus, and others,

Please confirm that I understood your explanation and demonstration correctly.... it is possible to create a 3D video of the moon?
Yes, it's the same principle as photography. As you note, a 3D moon taken on different sides of the earth could not include any foreground, as they would be too different (obviously). The word for this is 'retinal rivalry'.

Anything should work, as long as you can get a different view in the left and right eyes. You could even use the rotation of a planet or the sun as a means to fake 3D. Terrestrial planets may work better as the rotation on gas bodies is differential between the poles and the equator, but how much of a difference that makes remains to be seen. Anyone want to send me some data? Any images with around 5 degrees or rotation between pics?

Quote:
Originally Posted by Sol-Skysailor View Post
Including for a magnified part of the moon, at crescent limbs -or at full moon if such lighting would work. For 3D craters and rilles?
I think here you would have to use your pre-mentioned plan to have distant observers photograph the moon at the same time, because the phase would have to be exactly the same, as would the libration, since you're going for details. You don't want the lighting of those craters to shift between shots, only the observer's position.

Also, one thing to be careful of when making your own 3D images, you want the images to be slightly different, yes, but in the x (left - right) plane only
.

You don't want the same feature to have a different y position (height). So if your two images of the moon have an axis of difference that runs anything other than vertical, you will need to rotate the images to achieve this.

Quote:
Originally Posted by Sol-Skysailor View Post
The 3D processing could be organised after, do you think? Like, the red/cyan or polarising even though producing images of images would work well?
l
Quote:
Originally Posted by Sol-Skysailor View Post
Yes, after reading your explanation I thought hey images at libration opposites should work then. Amazing what you explained and showed. I have (had) magic eyes but my eyesight has changed unevenly so will stare at them some more.
It takes a little practice to do the cross-eyes 'free-viewing' thing. The trick is, when cross-eyed, to try overlay the right moon image in the left eye over the left image in the right eye, then try to focus; thus forming a composite in the middle. Or if you have a stereoscopic screen, try Stereoscopic player, which will play back pretty much any 3D input format in any output format. And if you have the anaglyph glasses (red/cyan) it'll do that too. In fact, the moon is pretty much the perfect subject because it's largely colourless. With colour separation 3D, the more brightly coloured an object is (particularly towards red/cyan) the more it tends towards retinal rivalry (unless you make it black and white before applying anaglyph processing).

Quote:
Originally Posted by Sol-Skysailor View Post
Markus, you're heaven sent for 3D. Lucky for us you saw the questions and kindly reponded.
l
No Problem. There 's so much knowledge here that it's rare that discussion revolves around a field that I can usefully contribute to. That's what forums are about, in the end.

Cheers

Markus
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Old 13-11-2016, 01:30 PM
Sol-Skysailor (Sol)
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Thank you, Markus!

Anyone, please, who are already comfortable with using FB, Twitter, etc, please tweet out info and/or this link to encourage image and video capturing (with time stamp, I think) from example locations: Sth Afr to Finland, Hobart to Sapporo, Adelaide to Kyoto, South Argentina or Chile to East Canada. Could be as a comment at the end of topical NASA news for astrophotography too?


A citizen-experiment.

Fingers and toes crossed
(eyes not cross, I look beyond the images.)
Sol
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Old 13-11-2016, 02:40 PM
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By way of example, I took some SOHO data and made a 3D sun. It's not perfect because, as you know, the sun changes quite markedly day to day, but it is close enough to give a sense of 3D. It's only a short 2 second test and youtube compresses the bejeesus out of it.

https://www.youtube.com/v/mQAKx45fft...st=mQAKx45ffts

X-eyed format again, but if you have a viewer, just switch the eyes.

Markus
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Old 21-11-2016, 09:41 PM
Sol-Skysailor (Sol)
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Hi All,

Thank you, Markus, very especially, for making all these 3D images and videos happen. I'm admiring and I'm grateful. I see the success of this experiment/project quite crucially in your hands and those who took or will take images.

Markus, and anyone who can help , please go for it freely. I like to promote teamwork without competition (except in a minor way for fun and celebration afterwards), and personally have been practising reducing my ego or whatever word can describe it -meaning that I don't claim to own an idea, because everything builds on other things. Would love to see achievements happen.

In my limited ways I have
1) written a comment, as below*, for Jerry Lodriguss’ story webpage
http://www.astropix.com/wp/2016/11/1...gee-full-moon/ after he posted excellent images here and also one got on to the APOD. But my comment didn't appear.
2) written to an address I believe is in Japan. Planned to write to selected astro societies -you never know, might work.
3) searched (need to do more -please everyone help). Surely surely images and videos of the special Supermoon (perigee moon if the S word triggered whatever) and any moon already EXIST -we've just gotta find them and say hello to the owners.

Lastly, Markus, I don't have a CN a/c yet -waiting till I could contribute something relevant. Since people seem to be judged by #posts I should think others with high counts would be more effective. Or anyone using social media. So go for it!

All fingers, toes, eyes.... crossed.

Sol


* An example comment, please of course edit or rewrite as you wish. Could use 'and team' or 'et al.' if you want to. I have no requirements.

Thank you for excellent images and articles, and for sharing them on iceinspace.com.

It is hoped that your astrophotographer readers from far distant apart would share quality images or videos of this particular perigee moon, Supermoon, for an experiment on producing 3D. (Just for the occasion of it, later other moon shots would work especially if coordinated, and hopefully of detailed telescopic features too.)

Vision is ‘world eyes’ watching moonrise or moonset in 3D, or when higher up at perigee or at full, or seeing detailed moon features in 3D. The concept is being discussed at http://www.iceinspace.com.au/forum/s...d.php?t=150321

[Quote] Example locations: Sth Afr to Finland 10254 km, Hobart Sapporo 9569 km, Adelaide Kyoto 7778 km. And somewhere in Argentina or Chile to somewhere in Canada [Unquote]

They should be of the moon alone, ie without a local structure defacing it (foreground like the ocean and reflection we can edit/process and could even be desirable); but….. where possible, if we’re really lucky, with mid-ground like the ISS nearby or background like any bright stars that could potentially help with realistically placing other celestial objects.

As it is an experiment other ideas and techniques may unfold. Global teamwork and exploring encouraged. Any advice or participation would be most appreciated.

Many Thanks!
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Old 22-11-2016, 10:57 AM
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Yes, it's the same principle as photography. As you note, a 3D moon taken on different sides of the earth could not include any foreground, as they would be too different (obviously). The word for this is 'retinal rivalry'.

Anything should work, as long as you can get a different view in the left and right eyes. You could even use the rotation of a planet or the sun as a means to fake 3D. Terrestrial planets may work better as the rotation on gas bodies is differential between the poles and the equator, but how much of a difference that makes remains to be seen. Anyone want to send me some data? Any images with around 5 degrees or rotation between pics?
Damien Peach's latest Jupiter animation should work nicely - https://www.youtube.com/watch?v=7bIkCVolXDk

As for other candidates for 3D night photography, maybe concentrate on the ionosphere or near space environment? Meteors, meteor smoke trails, airglow, aurora, rocket stage plumes, ISS, satellites, etc. Personally, I've tried meteors. During one Perseid night I ran 2 cameras separated by 10 km baseline and managed to get a couple of meteors in 3D. The trick is to synchronise the cameras over long distance.
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Old 12-12-2016, 11:32 AM
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Hi, Anyone going for the perigee'ish(?) full moon, or other objects, that might help with this 3D experiment, please?

Markus, just wondering if you had any response via CN or other means? I have been busy and not progressed further myself but real keen to see it happen some time.

Cheers
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Old 12-12-2016, 11:43 AM
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No, I haven't. This end of the year all gets a bit silly.

I was thinking that to get anything other than a full or gibbous moon, the configuration of observers would require that one shot would have to be a daytime shot of the moon. I can shoot an early evening shot of first quarter, but to get a good baseline, someone else would have to shoot the moon as it follows the sun into the sky around lunch-time.

So I'm wondering if we can get shots from a daytime moon that will match sufficiently. I'm sure it's possible, hell some people here have managed spectacular contrast on Jupiter during the day. But I will need to run some tests to make sure *I can do it before asking others to participate.

-Markus
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Old 16-12-2016, 10:51 AM
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Hi Markus,

Good that what you did has generated interest. It reads like you're after people following the moon along the latitudes, approximately. I was referring to two people on the same longitude simultaneously imaging the moon just as two eyes would, i.e. 'world eyes'. Am I understanding correctly that the same-longitude method would work?

I hope both methods get trialled. For myself with not much skill, it's like if I can't be an astronaut I'm willing to be in the road gang, or if I can't be in the cook fire I can be just a matchstick. They are often placed in the lowest rung as 'can't-do'. For an innovative environment matchsticks are encouraged and the team take on.

Thank you. Looking forward to seeing things! :-)
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Old 16-12-2016, 11:13 AM
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Hey, Sol,

well I posted in Cloudy Nights but it didn't generate much interest. There was one guy who had generated quite impressive results by simply phase matching and using the librations to get a different view.

In answer to your question, you can use any separation you like, longitude, latitude or a mix of the two, but the orientation determines the orientation of the final image. Let me explain.

So you take a nice shot of the terminator at, say first quarter. It's a typical shot with the terminator running vertically through the image.

Simultaneously, your friend at the same longitude in the northern hemisphere takes the same shot.

When you put them together, they will look weird and hurt the eyes. The reason is because the baseline in the photo - the separation between the eyes - runs vertically not horizontally. When you look at the image, the pictures you are seeing are exactly as if your eyes have been reconfigured in your face so that one is directly above the other. It's a very strange feeling and our brains are not equipped to deal with it.

The solution to this Picasso-isation or the senses? Turn the picture 90 degrees. One way will invert the 3D, the other will give you the correct 3D. A lot of 3D systems can't deal with tilting of the head. If you have anaglyph glasses, try it.

Anyway, you end up with a first quarter image that has its terminator in the horizontal plane with the limb hanging above or below, and no other orientation will work because it is 'baked in' by the angle between the two observers. Correctly gauging the direction of the baseline in the images is one of the most important steps in post.

Hope that helps!

Cheers

Markus
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Old 30-01-2017, 10:20 PM
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Hey Markus,

Thanks for the clear explanation. Sorry tardy reply; bin bizzi.

Yes, I had worked out what would happen when ‘tilted head’
and ‘object in the middle between two eyes,
each looking towards the other.


So, yes, you were describing techniques (clever) other than
my proposed straight-forward taking images/videos of an object
say nearer the horizon (disregarding the atmospheric effect for now),
at the same time
one in the NH and one on approximately the same longitude but in the SH.

As that would work, therefore.... when the object rises high up in the sky
say to the meridian I thought it would be the same situation
IF each 'person with eye' lies down and sees the object not from the opposite
side but as if it were near the new horizon.
In this case each eye is NOT directed towards the other.
This means the camera-eye would 'lie down'
ie not directed in each other's direction.

I didn't think it would be exactly the same as
having each camera up then turning the images 90 deg.
I will re-read your explanation some more.

Hope there will be interests and joint efforts at some stage.

People missed posts, so we ET will keep calling.
One day IIS may have a …………. 3D………… subforum.

Then ……….. VR…………

Cheers
Sol
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Old 30-01-2017, 10:49 PM
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I was trying to say it *would work, but you have to be careful about the orientation of the pictures, as the baseline will determine the orientation in the final image.

Sorry if my long winded reply was confusing!

:-)

Markus
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