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Jason_Roberts
2009-May-02, 08:38 PM
The Astrophoto stereograms are just about the coolest thing I have ever seen. I love them. Example. (http://www.universetoday.com/wp-content/uploads/2009/02/ngc6543parallel.jpg)

I was wondering if whoever makes them could reveal how they are done. I tried just mirroring an image next to itself alone won't do the trick. There are certain features of the image that are made to stand-out while ones on the other image are made to appear "behind" those objects.

Is there a program someone uses to create stereograms?

I would be really interested in how these are done.

trevorw
2009-May-06, 07:27 AM
This is was done using Photoshop is this what you had in mind

Regards

Jason_Roberts
2009-May-06, 07:22 PM
This is was done using Photoshop is this what you had in mind

Regards

I see you tried to attach an image, but for some reason it didn't show up in the post.

EDIT: I can see it now.

Yup. I mean those.

I tried just mirroring an image next to itself, but I had no luck in creating the same effect where specific areas where made to stand out more than the others. I figure one image is off-set or changed in some barely noticeable way to complete the illusion.

For instance the image you posted actually appears to be very flat, whereas the one shown here (http://www.universetoday.com/wp-content/uploads/2009/05/ic4406-parallel.jpg) has a very clear and 3-dimmensional concave "bow" towards the center of the nebula. The 3D effect is even more apparent in this image. (http://www.universetoday.com/wp-content/uploads/2009/04/ngc602-parallel.jpg)

I might need to upgrade from the "magic eye" illusions and just get a pair of those silly glasses.

mahesh
2009-May-28, 11:55 AM
Hey JR / trevorw....

these are lovely three dees!

I just thought of Nyberg's Apollo compositions...but they aren't strictly 3-Ds, but have great effect.
They are stitched / scanned from the original Hasselblads
http://www.panoramas.dk/moon/mission-apollo.html

Another thought, of a distinguished stereo-astrophotographer, Jukka Metsavainio, whose compositions have graced the BAUT board and UT newsletters. Perhaps you could touch base with him (guru-wise), for further tuition / guidance, as it were.
http://www.universetoday.com/wp-content/uploads/2009/05/fullmoon_parallel-copy.jpg

Back in the seventies, Viking landers on Mars, I was given a NASA book, of fantastic photographs of Martian surface, with a large bunch of them three-dimensional. My knees still go jelly, looking at them. I am there.

mahesh
2009-May-28, 12:10 PM
Off the top of my head....
JR, you know you could also ask Mr RickJ, here. I am sure he could point you in the right direction.
Also Galactic2000 (John Chumack). With such great mentors around, one doesn't have to look far at BAUT.

edit:
JR, if you could / would like to, have this thread moved to astrophotography section, you could have more exposure there, response-wise.

mahesh
2009-May-28, 12:42 PM
JR....
you've got me rolling with this 3-D stuff...i would've thought that this would be the best :
http://en.wikipedia.org/wiki/Stereo_camera
some thing like this.

also I came across this camera thingie, for 'digital' users....
http://www.photo3-d.com/HowPhoto3DWorksPage.php?session=

cool. but the camera is being only, only, 'slid' across the attachment, the same distance, like for correct ocular vision...few inches...as it would happen with the two lenses, of a normal fully functional stereo camera.

I'm going to try this. moving the (cellphone :D) camera few inches, repeating shots...see if it works without having to 'buy' the attachment. (am broke).
i wonder how many times we've all shot stereo pictures without realising.

ps: i like the glasses, though. cool.

Jason_Roberts
2009-May-31, 03:29 PM
Thanks for the replies Mahesh!

I think there is a varied number of ways to approach making stereograms. At first I was under the impression that there was only one way to do them. After some searching I found there were a multitude of ways to approach constructing these, and that there many different 'types' of stereograms as well.

Wow, almost forgot this thread was here! Thanks for flagging me down.

HenrikOlsen
2009-Jun-01, 02:13 PM
I tried just mirroring an image next to itself alone won't do the trick.
Mirroring will definitely break the illusion, since that's not how the eye sees distance.

The thing to do is to copy, not mirror, the image next to itself, then distort one or both slightly so the parts that are supposed to look like they are closer are moved a bit nearer the other copy, ie. moved horizontally to be nearer nearer the vertical line between the images.

selden
2009-Jun-01, 05:53 PM
One way to produce 3D stereograms of the stars is to use a 3D astronomical visualization program and make screengrabs from appropriate viewpoints.

eburacum45
2009-Jun-02, 07:43 PM
I thought I'd give that a go, using Celestia (and Gimp)
http://eg.orionsarm.com/im_store/med_orion3d.PNG
this is supposed to be the Orion Nebula, but it is a bit too square. I'll have to make another, larger billboard with a larger texture fading out towards the edges. Trouble is, the Orion Nebula seems to fade out at the edges for quite a long way; it's difficult to know when to stop.

Jason_Roberts
2009-Jun-03, 07:28 PM
I thought I'd give that a go, using Celestia (and Gimp)
http://eg.orionsarm.com/im_store/med_orion3d.PNG
this is supposed to be the Orion Nebula, but it is a bit too square. I'll have to make another, larger billboard with a larger texture fading out towards the edges. Trouble is, the Orion Nebula seems to fade out at the edges for quite a long way; it's difficult to know when to stop.

I've found that the clone brush in Photoshop is really handy for this. I would take an image, mirror it side-by-side, and then use a "smart lasso" selection tool to highlight the entire area I wanted to bring forward in the illusion, and 'scooting' it to the side. This will leave gaps and missing data patches in the image, which you can use to clone brush to fill in and blend together with the adjacent picture seamlessly. With this I seemed to have found a way to make multiple levels of depth instead of just two.

EDIT: Ah, never mind eburacum. I understand what you mean now. I just gave it a try and had the same problem.

Nebulous things seem to be really tricky.

Jason_Roberts
2009-Jun-03, 08:04 PM
Here's one I made from http://apod.nasa.gov/apod/ap090515.html

Though, it's probably not at all accurate. I've probably made the far stars close and the near objects distant. But it's a somewhat fair example of what I was describing.

I guess the attach image function isn't working at the moment. Here's the URL: http://i59.photobucket.com/albums/g287/robertsthevile/owlstereo.jpg

eburacum45
2009-Jun-03, 09:29 PM
Nice image!

Selden posted an interesting link over at Celestia to a rather more sophisticated method for creating fully 3d models of planetary nebulae;
http://www.cg.cs.tu-**.de/people/wenger/3dnebula/wscg.pdf
this method gives some interesting results, apparently, but it isn't the sort of method that can be downloaded and used on home computers (not yet, anyway).

Celestia does have a number of 3d models of nebulae available for download, but they may not satisfy purists as a certain amount of artistic licence has to be used to make them.
http://celestiamotherlode.net/catalog/nonmessiernebulae.php

eburacum45
2009-Jun-03, 09:59 PM
(I really admire the Eta Carinae model from that list, by the way; it compares very well with the real thing).

Jason_Roberts
2009-Jun-03, 10:15 PM
(I really admire the Eta Carinae model from that list, by the way; it compares very well with the real thing).

Wow, it really does.

All it's missing is a slight violet tint towards the center from the star itself.