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Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 5:38 pm
by Spif
Is that left side image the best resolution we have?

Or is there a full resolution image available somewhere?

-s

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 6:07 pm
by Coil_Smoke
Coil_Smoke wrote:There must be some distortion in generating this stereo pair. When I get the images to merge, a very elongated ' water melon ' shape appears. Like viewing a water melon end on. I have seen no other images that show Pluto is shaped like this.
Is no one else getting the water melon effect ? I have seen this stereo pair twice and saw the same thing. As for viewing these stereo pairs, I just relax my eyes and allow the two images to drift towards the center. Then there are three with the 3D effect locked in the center. Forcing my eyes to cross does not work for me.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 6:48 pm
by Chris Peterson
Coil_Smoke wrote:
Coil_Smoke wrote:There must be some distortion in generating this stereo pair. When I get the images to merge, a very elongated ' water melon ' shape appears. Like viewing a water melon end on. I have seen no other images that show Pluto is shaped like this.
Is no one else getting the water melon effect ? I have seen this stereo pair twice and saw the same thing.
No, the effect is real. Probably the result of this not being a true stereo pair, but rather two images made at different times, with both spacecraft motion and planetary rotation combined. Also, the spacing is very large, which gives a diorama effect that emphasizes the distortion.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 7:55 pm
by geckzilla
I can do the cross-eyed version (Henry's) but not the wall-eyed one (APOD). I've always found cross-eye easier to do. I can only get 1/3 to 1/2 of the way there the other way.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 8:08 pm
by henrystar
Chris Peterson wrote:
stereouseless wrote: You can learn to point your eyes independently (like a chameleon) and amaze your friends and possibly advance a career in comedy... all harmlessly.
Good heavens! I'm not going to try that. But what I learned long ago that I CAN do and HAVE learned to do, is hold up either hand, flat --- and have either the little finger by itself, or the next finger by itself bend at right angles. Just takes practice!

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 8:13 pm
by Chris Peterson
geckzilla wrote:I can do the cross-eyed version (Henry's) but not the wall-eyed one (APOD). I've always found cross-eye easier to do. I can only get 1/3 to 1/2 of the way there the other way.
Without special training, normal eyes can go from very cross-eyed (as when you look at a close object) to parallel (as when you look at an object at infinity). Normal stereo pairs need to be of a size such that when you look at them, you aren't trying to drive your eyes outwards beyond parallel (which is physically possible, but difficult without practice).

The trick in either case is decoupling the focus from the position. When we look at a normal stereo pair, our eyes are positioned for infinity but focused for nearby. When we look at a crossed-eye stereo pair, our eyes are positioned for a very close object but focused somewhat beyond that.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 8:22 pm
by Ron-Astro Pharmacist
I'm having the same difficulty as some of the others. Is the technique similar to looking at a stereogram?
Star.jpg
I can make out the star but not a stereo Pluto.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 8:26 pm
by geckzilla
It's exactly like that, Ron.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 8:31 pm
by Chris Peterson
Ron-Astro Pharmacist wrote:I'm having the same difficulty as some of the others. Is the technique similar to looking at a stereogram?

I can make out the star but not a stereo Pluto.
Yes, it's the same. But with the random dot stereogram, you don't have to change the direction your eyes are pointing very much, so you don't have that major decouple between focus and position.

Do you see the star coming out of the image or going into it? If the first, you are deviating your eyes slightly outwards, like you need to do in order to view today's APOD. If you're seeing the star sinking inwards, you're viewing the stereogram cross-eyed, the way you need to view Henry's switched version.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 9:04 pm
by Ron-Astro Pharmacist
Chris Peterson wrote:
Ron-Astro Pharmacist wrote:I'm having the same difficulty as some of the others. Is the technique similar to looking at a stereogram?

I can make out the star but not a stereo Pluto.
Yes, it's the same. But with the random dot stereogram, you don't have to change the direction your eyes are pointing very much, so you don't have that major decouple between focus and position.

Do you see the star coming out of the image or going into it? If the first, you are deviating your eyes slightly outwards, like you need to do in order to view today's APOD. If you're seeing the star sinking inwards, you're viewing the stereogram cross-eyed, the way you need to view Henry's switched version.
Yes. I was seeing the star(s) up above the background coming out of the image. I was able to start to view the stereo Pluto as a series of three objects but it hasn't come into 3D yet. I think it's easier for me to spread my gaze outward as you are talking about but more difficult to cross them. It does take some training. Looking at a variety of stereograms seems to be training my eye muscles to do what I want them to.

Wouldn't it be nice to use an exercise like this to help with the curse of old eyes – reading glasses? :evil: Wishfull thinking - that has do another set of muscles but this is still a good for seeing in 3D.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 9:08 pm
by ezucker1
Even after the images are reversed, I find that they don't make a very good 3D image. I believe this is because of the significant differences in resolution between the two images. We would need to images of comparable resolution to make a better 3D image.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 9:39 pm
by Chris Peterson
ezucker1 wrote:Even after the images are reversed, I find that they don't make a very good 3D image. I believe this is because of the significant differences in resolution between the two images. We would need to images of comparable resolution to make a better 3D image.
As a rule, you can significantly blur one side of a stereogram and see little loss of detail. Our brain takes the high frequency information from the sharp side and combines it with the 3D information from the pair. A cute trick. Personally, I find it very difficult to detect that one side is fuzzy in this image once I've merged them.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Thu Aug 06, 2015 9:58 pm
by Chris Peterson
Ron-Astro Pharmacist wrote:Yes. I was seeing the star(s) up above the background coming out of the image. I was able to start to view the stereo Pluto as a series of three objects but it hasn't come into 3D yet. I think it's easier for me to spread my gaze outward as you are talking about but more difficult to cross them. It does take some training. Looking at a variety of stereograms seems to be training my eye muscles to do what I want them to.
Yeah, it just takes a little practice. What I suggest is look through the screen. That is, let your eyes relax like you're looking into the distance. That will allow the images on the screen to merge, they'll just be out of focus. But once you fuse them, that tends to lock in, and then you can work on bringing your focus back in. And start far from the screen. From 10 feet away, it should be easy. Then work your way closer.
Wouldn't it be nice to use an exercise like this to help with the curse of old eyes – reading glasses? :evil: Wishfull thinking - that has do another set of muscles but this is still a good for seeing in 3D.
Actually, the loss of accommodation with age has nothing to do with the muscles that shape the lens, but with the lens itself losing flexibility. So no amount of exercise will help. But there may be pharmaceutical solutions in the near future, or artificial lenses that aren't fixed. Some people who have had cataracts removed have had the lenses replaced with focusable lenses. We're getting there.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 1:19 am
by Boomer12k
Mother told me not to do that....or my eyes would stick like that... :D

Too bad we don't get to stay around and look more...

:---[===] *

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 1:22 am
by BMAONE23
Ron-Astro Pharmacist wrote:I'm having the same difficulty as some of the others. Is the technique similar to looking at a stereogram?
Star.jpg
I can make out the star but not a stereo Pluto.
That's an interesting one. Stopping at the first point of intersection yields a 5 point star but if you continue to the next point of intersection, you get a double pointed 5 point star that raises like a tower in the middle

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 8:15 am
by 3D or not 3D
It is quite amazing that there has been so much confused discussion as to whether this is a stereo pair - or not. Whether the images are the right way around - or not. Clearly before scribbling down their incoherent thoughts, none of these confused people bothered to look up ANYTHING about stereographs, let alone look at Brian May's site dedicated to the subject. Maybe you expect to be spoon fed by APOD to tell you exactly what to do to see the 3D image? Go away and look at all the information available at The London Stereoscopic Company, and in future think very carefully before being so willing to show your complete lack of understanding of a topic, especially when you haven't even bothered to take the first step of looking it up online.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 3:06 pm
by Chris Peterson
3D or not 3D wrote:It is quite amazing that there has been so much confused discussion as to whether this is a stereo pair - or not. Whether the images are the right way around - or not. Clearly before scribbling down their incoherent thoughts, none of these confused people bothered to look up ANYTHING about stereographs, let alone look at Brian May's site dedicated to the subject. Maybe you expect to be spoon fed by APOD to tell you exactly what to do to see the 3D image? Go away and look at all the information available at The London Stereoscopic Company, and in future think very carefully before being so willing to show your complete lack of understanding of a topic, especially when you haven't even bothered to take the first step of looking it up online.
Not everybody has learned good research skills. This forum is about asking questions, about discussing concepts that may be unfamiliar to many people. Even if those answers might be available elsewhere.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 5:51 pm
by Cousin Ricky
The problem with direct stereographic images is that my eyes simply refuse to merge images more than about 6 cm wide. I think the people who can do “free” viewing with images this large must have double-jointed eyes.

On the other hand, I never have trouble with cross-eyed images.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 5:59 pm
by Chris Peterson
Cousin Ricky wrote:The problem with direct stereographic images is that my eyes simply refuse to merge images more than about 6 cm wide. I think the people who can do “free” viewing with images this large must have double-jointed eyes.

On the other hand, I never have trouble with cross-eyed images.
Well, we evolved to look at things ranging in distance from infinity to the tips of our noses. So it's hardly surprising that we can only comfortably move our eyes between parallel and cross-eyed. And parallel implies that the widest images we can readily merge will be spaced no more than our interpupillary distance- a bit over 6 cm for adults.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 6:18 pm
by neufer
Chris Peterson wrote:
Coil_Smoke wrote:
Coil_Smoke wrote:There must be some distortion in generating this stereo pair. When I get the images to merge, a very elongated ' water melon ' shape appears. Like viewing a water melon end on.
Is no one else getting the water melon effect ? I have seen this stereo pair twice and saw the same thing.
No, the effect is real. Probably the result of this not being a true stereo pair, but rather two images made at different times, with both spacecraft motion and planetary rotation combined. Also, the spacing is very large, which gives a diorama effect that emphasizes the distortion.
"APOD: Stereo Pluto" allows one (unnaturally) to see around the backside of a rather large (and distant) Pluto.

The only way the mind makes sense of this is to assume Pluto is really melon shaped.

Henrystar's cross-eyed Plutos (reduced to plum sized spheres that one is
used to seeing around with crossed eyes) doesn't suffer from this problem.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 6:39 pm
by Cousin Ricky
A cross-eyed pair. Image credits are embedded.
Pluto cross-eyed stereo pair.
Pluto cross-eyed stereo pair.
Edit: Ah, Neufer, you beat me to it!

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Fri Aug 07, 2015 9:19 pm
by geckzilla
Cousin Ricky wrote:Edit: Ah, Neufer, you beat me to it!
Henry beat you to it. :)

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Mon Aug 10, 2015 9:32 pm
by neufer
Click to play embedded YouTube video.
Chris Peterson wrote:
stereouseless wrote:
dear chriss.. i still say its a big waste of time to put these images here... looking crosseyed at something is not good for ones eyes.
You don't look cross-eyed with this image. However, training your eyes to view stereo pairs is not harmful. Indeed, there are specific eye exercises that do just that, with therapeutic intent. You can learn to point your eyes independently (like a chameleon) and amaze your friends and possibly advance a career in comedy... all harmlessly.

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Tue Aug 11, 2015 3:46 am
by alter-ego
Yeah, to explore the interpretive viewing of the spherical- vs melon-shaped Pluto, I had some fun with viewing the image below. It combines both concave and convex images at the same time. When locked in, the central two images show both image types. At times I didn't know which way my eyes were pointing :). I'll say though that think the melon shape was pervasive in both convex and concave views, but not as clear when concave.
Again, for best simultaneous viewing, click the picture and optimize the browser magnification to maximize image size for relaxed-eyes view. Cross-eyed viewing allows for larger eye-pointing difference so you might easily see the cross-eyed view but not the other at the same time.
Crossed-eyes Convex sphere on left, concave on right, or Relaxed-Eyes convex "melon" on right, concave "melon" on left
Crossed-eyes Convex sphere on left, concave on right, or Relaxed-Eyes convex "melon" on right, concave "melon" on left

Re: APOD: Stereo Pluto (2015 Aug 06)

Posted: Tue Aug 11, 2015 10:41 am
by starobin
I rotated the original picture 180° to make the stereo image appear convex. It sure beat standing on my head!