Wednesday, July 14, 2010
Rosetta at asteroid Lutetia
Red-Cyan stereo anaglyph of asteroid Lutetia created from ESA images. You will need red-cyan glasses to see the 3D effect.Around the same time Spain was beating the Netherlands in the World Cup, the comet chasing spacecraft Rosetta passed close by asteroid Lutetia.
You can read the story and see some fantastic images at the ESA website, and you can download images from here.
I made a 3D anaglyph from two consecutive images using the GIMP, they asteroid rotated too much for a good 3D effect, but you can still see the cental blug quite well.
Labels: anaglyph, asteroids, stereograms
Thursday, January 14, 2010
The Southern Cross in Stereo
Space is big, very, very big. And the stars are very far away. Even though the stars are all different distances from the earth, they are so far away that they all look as if they are painted on a dome.The get the same sort of change in perspective that we would get looking at ordinary objects if we moved just one meter, you need to move light years.
To demonstrate this, with the aid of Celestia, I've made a cross-eyed stereo image of Crux, the Southern Cross (the red-green anaglyph didn't give a strong stereo effect). Stare at the picture and cross your eyes until the x of Crux aligns, and the stereo version will pop out at you (you can click on the image to embiggen and get a higher definition view).
I made this by taking an image of Crux as seen from Earth using Celestia, then moved to Alpha Centuari A, 4 light years away, for the second image of Crux. Then I cropped and assembled the images in the Gimp for optimal stereo effect.
4 ligt years. For most objects, you can get perspective effets by hopping from one foot to the other, hopping 4 light years is a bit more difficult.
Labels: Astronomy, stereograms
Thursday, November 26, 2009
Enceladus's plumes in 3D
The plumes of Enceladus as a red-cyan 3D anaglyph. You will need red-cyan glasses to see it in 3D. Original image credit NASA / JPL / SSI /. (click to embiggen)
Over at the Planetary Society blog Emily has been posting astounding images from the latest fly by of Encaladus. See here, here and here.
Astounded by the cross-eye stereo images Emily posted, I've made my own red-cyan anaglyph for people who can't go cross eyed. Now go and read Emily's pages or go to the raw image website.
Labels: anaglyph, Satellite, Saturn, stereograms
Sunday, December 28, 2008
Hand Drawn Anaglyphs!
You may be familiar with red/(cyan or blue) anaglyphs. These are pictures where a 3D effect is produced by overlapping red and cyan (or blue) images. I have used anaglyphs to make stereo images of Mars and the Sun, for example.A couple of days ago MiddleOne asked if you could draw 3D pictures. I thought it was possible from my experience with anaglyphs, and we experimented with various coloured textas, but with only minor successs.
Around 5:30 this morning SmallestOne kicked me out of bed, and I started thinking (or maybe I was already dreaming) about anaglyphs. I couldn't go back to sleep, so I tried experimenting. First you need the right colour textas. Our stereo glasses have red for the left eye, and cyan for the right eye. You need a red colour that will be invisible through the left eye, and dark through the right eye, and a blue/green that is invisible through the right eye and dark in the left eye.
It was pretty easy to find a light red text that fitted the bill (our previous attempts had used too dark a red). Finding a blue-green that worked was much harder, and I had to settle for a pale green/blue that sort of worked.
Once you have your colours, then how do you match them up to give depth? I started with simple squares. Blue-green lines to the left of the red lines make the boxes appeare below the picture plane, blue-green to the right makes the boxes appear above the picture plane. The wider the lines apart, the greater the feeling of depth. by grading the line spacing, you can give a feeling of volume to the surface.
You also have to choose your viewing postion, straight up and down at about a meter away works best.
The planet with craters and rings above is the result. Viewing with red/cyan glasses about a meter away gives a nice 3D effect for the cratered body of the planet. The rings are a little wobbly though, but still, this was a hand drawn image using only red and blue-green textas. A little practise (and a better shade of blue-green), and you can draw stunning 3D images without fancy computer graphics programs.
Labels: sketch, stereograms
Sunday, July 08, 2007
Stereo Anaglyph of the Sun
Image credit STEREO.I've written before about making stereo images from the STEREO SECCHI beacon images. For the image to the left, all you have to do is cross your eyes, until the images are superimposed, and viola! A 3D image appears. To make this kind of image, you basically just need to copy the ahead and behind images align them and place
them relatively close together, and you have a 3D image. I say basically, as the ahead images are bigger that the behind images, you have to rescale them. I download 512x512 images and rescale the ahead image to 455 x 455. Also, if you are downloading images other than those on the beacon images page, make sure you download images with the same date stamp as the beacon images, otherwise the features on the Sun won't link up properly.The lower image on the left is a stereo anaglyph of the Sun. For these images you need coloured spectacles, with one red and one blue panel (like they give out at 3D movies). While the "crossing eyes" 3D image doesn't require any hardware, many people just can't cross their eyes to form stereo images, and anaglyphs work for everybody. Anyway, this image was created using the Gimp. I was alerted to this use of the Gimp by Peter Tagatac of Top of the Lawn, but never had an astronomical use for it until now.
The full details of how to make an anaglyph with the Gimp is in this tutorial, so I won't repeat them here, but just point out some STEREO specific issues. As for the "crossed eyes" version, you will need to rescale the ahead image (and make sure you have the matching ahead and behind images). As well, it's important that the ahead image is the cyan filtered image, and the behind is the red filtered image (otherwise the 3D effect is mucked up). You will also need to overlay the images. After you have followed the tutorial instructions to create the red and cyan layers, turn the colour layers off, select the top image layer and set the layer attribute to difference, then move the top layer until the images are aligned. Then return the layer attribute to normal, restore the colour layers and proceed as with the tutorial.
Labels: anaglyph, Stereo Satellite, stereograms, Sun
Tuesday, April 24, 2007
I Scoop NASA!
Stereo images of the Sun, cross your eyes to see the Sun in 3D (Image Credit NASA/STEREO).For the first time I've scooped someone. NASA just put out a press release annoucing the first stereo images of the Sun taken by STEREO. But I put up stereo imags of the Sun here and here last week! So I got there first!
Mind you, NASA's images are a lot better, but most require red-green stereo glasses to see. However they are fantastic, go and see.
Labels: Astronomy, Stereo Satellite, stereograms, Sun
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