Page 1 of 2

APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 4:14 am
by APOD Robot
Image 3D Mercury Transit

Explanation: On May 9, innermost planet Mercury crossed IN FRONT of the Sun. Though pictures project the event in only two dimensions, a remarkable three dimensional perspective on the transit is possible by free viewing this stereo pair. The images were made 23 minutes apart and rotated so that Mercury's position shifts horizontally between the two. As a result, Mercury's orbital motion produced an exaggerated parallax simulating binocular vision. Between the two exposures, the appropriately named planet's speedy 47.4 kilometer per second orbital velocity actually carried it over 65,000 kilometers. Taken first, the left image is intended for the right eye, so a cross-eyed view is needed to see Mercury's tiny silhouette suspended in the foreground. Try it. Merging the text below the images helps.

<< Previous APOD This Day in APOD Next APOD >>
[/b]

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 5:46 am
by Peter Clark
Please let's have more crossed eye 3D imagery! This is a marvellous pair, Mercury appear so vividly forward of the Sun and the captions appearing at 90 degrees to each other is a special treat!

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 5:47 am
by Peter Clark
Peter Clark wrote:Please let's have more crossed eye 3D imagery! This is a marvellous pair, Mercury appears so vividly forward of the Sun and the captions appearing at 90 degrees to each other is a special treat!

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 6:34 am
by SometimeStarviewer
By my eyes, the left and right images are reversed in this image. I used a graphics program to exchange the left and right images, and the 3D effect appeared. (Either that, or my optic nerves have reversed themselves!)

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 6:57 am
by Guest
I tried it and it didn't seem to work. The image kept jumping around and the horizontal alignment was critical. Then, after a beer, the image popped out very clearly, altho still careful alignment was needed. Great image pair.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 7:38 am
by philiparnold
Are you sure that you are not just trying to see how many of us will sit in front of our screens cross-eyed (it worked on me) my daughter came to see what was wrong with me :lol2:

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 7:50 am
by Boomer12k
Oh GREAT.... now my EYES ARE STUCK..... :lol2:

Nice Work...
:---[===] *

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 8:41 am
by heehaw
Thanks, interesting! I'm usually pretty good at crossed-eye 3D, but .... the lettering at the bottom is PERFECT 3D for me, really striking! But Mercury does NOT leap out at me, at all, it just looks like another sunspot. Puzzled! But nice try, I like the attempt.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 12:24 pm
by MadMan
I agree with SometimeStarviewer. The 3D didn't work for me until I reversed the position of the images in MS Paint.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 12:55 pm
by ThingFish
For those having trouble seeing the image, I suspect it's because you are trying to "uncross" your eyes, or move them as if to focus on more distant objects. For this pair you need to *cross* your eyes, moving them as if to focus on closer objects. I had the same problem at first. :shock:

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 1:51 pm
by MadMan
OK, here's the scoop. http://www.pikespeakphoto.com/viewing3d.html explains that there are two ways to free view 3D image pairs. I have always used the parallel method. The other method, cross-eyed, is new to me. Cross-eyed viewing allows for larger images. I may try to "get" cross-eye viewing. It's definitely harder and feels less natural.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 1:53 pm
by Mulecanter
My first time looking at a cross eyed 3D image--it really works!! and I don't have to wear silly glasses. I wonder if viewing Mercury's transit from our vantage gives any 3D effect since the distant is so great--shouldn't it appear 2D? Is this an artificial view?

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 2:09 pm
by zendae
That was so spectacular that we need to have more. As 3D as it gets! How about the Jupiter and Saturn families?

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 2:27 pm
by Jim Leff
Can someone please post the reversed images? Perhaps to Imgur, or other free easy image upload service?

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 2:55 pm
by pferkul
Jim Leff wrote:Can someone please post the reversed images? Perhaps to Imgur, or other free easy image upload service?
Here are the images swapped left and right for viewing using the parallel technique (focus eyes far away).

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 2:57 pm
by pferkul
I made a video of the moon crossing in front of the Earth using a similar technique:
Click to play embedded YouTube video.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 3:06 pm
by bigbaldjoe
There is another tick to help you see these. If you were to put a piece of clear glass in front of one of these images and focus on your reflection in the glass it helps some people see the 3d image.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 3:17 pm
by aildoux
Worked for me. Thanks.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 4:16 pm
by masodo
I have trouble with cross-eyed viewing and edited to add to my collection of parallel viewing images. (should have looked here first)

Image

Parallel viewing is relaxing and can be done for hours on end without the eyestrain associated with cross-eyed freeviewing.
I do appreciate that cross-eyed freeviewing makes it possible to view larger images but I am afraid someone will come up behind me and hit me in the back and my eyes would stay that way :shock:

I did a Blog on freeviewing - if you would like some help with parallel viewing:
http://blogdogit.com/article.php?story= ... 1134210875

:thumb_up:

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 5:47 pm
by NRCarlson9721
pferkul wrote:
Jim Leff wrote:Can someone please post the reversed images? Perhaps to Imgur, or other free easy image upload service?
Here are the images swapped left and right for viewing using the parallel technique (focus eyes far away).
Great- Thanks. The reversed images work much better for some reason. I use the "free viewing" technique often, but that's the first time flipping the images made such a big difference. I'll have to keep that in mind.

Norm

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 5:52 pm
by tomatoherd
Masodo:

I never had trouble w the Magic Eyes images. But I can't get the older stereograph images on your blog to superimpose, even w a sheet of paper from my nose down to the division between them on computer screen.
It may be a distance thing: on Magic eyes, the distance between images in less than an inch and a half. On the old stereographs, it's about 3 inches on center.
what'd'you think?

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Fri May 20, 2016 6:25 pm
by masodo
tomatoherd wrote:Masodo:

I never had trouble w the Magic Eyes images. But I can't get the older stereograph images on your blog to superimpose, even w a sheet of paper from my nose down to the division between them on computer screen.
It may be a distance thing: on Magic eyes, the distance between images in less than an inch and a half. On the old stereographs, it's about 3 inches on center.
what'd'you think?
If you are not used to freeviewing stereo pairs those may be rendering too wide.
Try doing a ([Ctrl] + "-") or otherwise zoom-out to get a comfortable width.

If you can do Magic-Eyes you should have no trouble with these once you get "dialed-in" :wink:

Thanks for stopping over, tomatoherd!

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Sat May 21, 2016 12:18 am
by SometimeStarviewer
A quick way to check whether the images are reversed is to mentally consider the line of sight from each eye. Lines drawn from your eye through Mercury to the Sun's surface will intercept that surface farther to the left for the right eye and farther to the right for the left eye. The eye to the right will see Mercury closer to the left limb, and the eye to the left will see Mercury farther away. Those intersections will be the perceived position of Mercury against the Sun's disk. As you can see from the two images here, the distances are reversed.

Another hint on this is that the bottom text was designed so that the large end is closer and the small end farther away when your eyes are crossed. The 3D effect for the images as presented is the opposite: the larger end is farther away, and the smaller end nearer.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Sat May 21, 2016 1:32 am
by Chris Peterson
masodo wrote:Parallel viewing is relaxing and can be done for hours on end without the eyestrain associated with cross-eyed freeviewing.
Actually, either is pretty relaxed with practice. The advantage of cross-eyed viewing is that you can cross your eyes a lot, but most people can't get their eyes farther apart than parallel (it's difficult or impossible to go wall-eyed, with your eyes both pointing outward). The consequence of this is that you can look at very large images with your eyes crossed, but are generally limited to small images (such that their centers are no wider than your eye spacing) for parallel viewing.

Re: APOD: 3D Mercury Transit (2016 May 20)

Posted: Sat May 21, 2016 3:02 am
by masodo
Chris Peterson wrote: Actually, either is pretty relaxed with practice. The advantage of cross-eyed viewing is that you can cross your eyes a lot, but most people can't get their eyes farther apart than parallel (it's difficult or impossible to go wall-eyed, with your eyes both pointing outward). The consequence of this is that you can look at very large images with your eyes crossed, but are generally limited to small images (such that their centers are no wider than your eye spacing) for parallel viewing.
I am practicing my crossed-eye viewing and it is getting easier but I do feel more tense doing it that way for some odd reason. Perhaps after a couple of adult beverages it would feel more natural :lol2:

So I guess the rule is: if your stereo pairs are presented 3 inches on center (or less) they should be assembled for parallel viewing (Stereopticon compatible) and larger images would naturally call for cross-eyed viewing.

This image when viewed - resized and - using "parallel eyes" was not very impressive - of course when I discovered the actual method of presentation and made the adjustment, the result was quite the spectacle. Many thanks to Stefan Seip for this commemorative work of art :clap: