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Sketching in 3D?

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#1 Jef De Wit

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Posted 20 August 2009 - 02:41 PM

Talking about my hobby, a friend asked if it was possible to make a astrosketch in 3D? My first guess is a rotating planet. Or working with the red/blue-pair of glasses. Did anybody tried or succeeded?

#2 idp

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Posted 22 August 2009 - 04:03 PM


I am not sure if I understand what you exacly mean, but in the case of planetary objects you can definitely have a 3D appearance in some cases so I guess it makes sense to wonder what's the best way to give this feeling in a sketch. I think of the Moon in particular, and Saturn under certain conditions. I remember seeing it "popping out" of the eyepiece when both the shadow of the globe on the ring and of the ring on the globe were visible with good seeing.
I fear I am not a good artist enough to answer your question though, hope someone else here around is.

IDP

#3 GlennLeDrew

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Posted 22 August 2009 - 04:34 PM

Jef,
I assume that you mean a *pair* of sketches which are representations as seen from two slightly different perspectives so as to yield a *true* 3-D appearance with suitable viewing apparatus.

If that's the case, then I can say that many, many years ago I experimented with simple perspective drawings that did result in very real depth perception when viewed either through lenses or via the crossed eye technique.

A more sophisticated astro sketch is indeed possible, but will take a bit of careful attention and time to execute.

#4 kraterkid

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Posted 22 August 2009 - 07:10 PM

Jef, IDP and Glenn,

I used to play around with 3D effects the same way Glenn describes his experiences, generally by shifting the shadows though and not so much changing the perspective. Here's a drawing I just did that kind of demonstrates the technique. You must know how to do cross eyed viewing and concentrate on the center image:

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#5 JimPie

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Posted 22 August 2009 - 11:25 PM

Jef, IDP and Glenn,

I used to play around with 3D effects the same way Glenn describes his experiences, generally by shifting the shadows though and not so much changing the perspective. Here's a drawing I just did that kind of demonstrates the technique. You must know how to do cross eyed viewing and concentrate on the center image:


Rich
:blackeye: That hurts way too much.

#6 Jef De Wit

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Posted 23 August 2009 - 06:48 AM

Rich, thanks for posting the sketch. It's a good way to create 3D in a sketch. But I don't arrive to get the two immages to one... Although I succeeded to see 4 craters!! Special view too!

#7 frank5817

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Posted 23 August 2009 - 07:50 AM

Rich,

It works for me. It helps to put the tip of your index finger below and between the two images about 8 inches from your face to get your eyes to merge the images.

Very nice Rich.

Frank :)

#8 idp

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Posted 23 August 2009 - 08:38 AM

Jef, IDP and Glenn,

I used to play around with 3D effects the same way Glenn describes his experiences, generally by shifting the shadows though and not so much changing the perspective. Here's a drawing I just did that kind of demonstrates the technique. You must know how to do cross eyed viewing and concentrate on the center image:


Excellent drawings and post. I wonder whether it would work the same for Saturn, for exemple by using sketches made at different times during the apparition, with slightly different breadths of the shadow and tilts of the ring. In situations like the one below I definitely happened to get a 3D felling.

IDP

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#9 Dee

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Posted 23 August 2009 - 12:30 PM

For some time now I have been considering doing a painting of this Lunar Anaglyph for interest and fun.

Dee

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#10 TenthEnemy

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Posted 23 August 2009 - 06:22 PM

This is really neat, here is my first attempt, done from a previous sketch of the ring nebula. I'm going to try some more by moving the stars around in some of my sketches on the computer.

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#11 TenthEnemy

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Posted 23 August 2009 - 07:05 PM

Here's a much better one, done in MS paint by simply moving stuff around on one side.

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#12 JayinUT

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Posted 23 August 2009 - 08:11 PM

Wonderful affect and it works but I can't hold it long. It literally makes my stomach upset.

#13 jcrew

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Posted 23 August 2009 - 09:03 PM

Is anyone else laughing imagining all the people sitting at their computer going cross-eyed?

Brad

#14 Jef De Wit

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Posted 24 August 2009 - 02:16 PM

Tenth Enemy, thanks for posting your 3D-sketches. Nice that it works for some, but not for me :snowedin:

#15 TenthEnemy

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Posted 24 August 2009 - 03:30 PM

To get these to work you should hold something like a finger or pen between the image any your eyes. Move the object in and out while focusing on it until the images merge in the background, now focus on the background while keeping your eyes crossed, remove the object if you need to. If you can't keep them merged just keep trying, your eyes should get used to it after a few tries.

If you back away from the screen it should be easier to get them to snap together and reduce any eye strain that you might experience because you won't have to cross your eyes as much.

I've got to stop making these, it's becoming addictive.

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#16 Jef De Wit

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Posted 25 August 2009 - 10:08 AM

Tenth Enemy
I tried and tried, but maybe my eye-muscles are too rigid...
Addictive is one thing, but don't take the risk that your eyes will stay crossed forever!

#17 Jef De Wit

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Posted 25 August 2009 - 03:36 PM

Hello
I tried all night long to make a (part of a) sketch 3-D. Put those special red/blue-pair of glasses on your nose. But like you will see... it doesn't work :bawling:
Although there is a psychedelic touch...

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#18 Jef De Wit

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Posted 25 August 2009 - 03:39 PM

The original in 2-D is still better. 30 cm Dobson, magnification x92.

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#19 starquake

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Posted 26 August 2009 - 02:02 AM

Wow, that's so cool! Those galaxies are really in the background! :) I have to try this technique too. :)

edit:

Ok, here's my first try:

M10 in 3D. It's not that perfect because it seems that some of the stars are behind the globular cluster, which is not possible.

Posted Image

#20 starquake

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Posted 27 August 2009 - 03:50 AM

I got the 3D fever. :)

Posted Image
M34 in 3D

btw, the key to create such 3d stereograms is that if you move a star to the right compared to the original, it will become a foreground star. if moving it to the left, it will become a background star. the more you move, the closer or farther it will be.

#21 starquake

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Posted 27 August 2009 - 06:29 AM

and m51 with NGC 5195:

Posted Image

btw, I found a cool use for this method: displaying double stars with their accurate position compared to eachother.

#22 TenthEnemy

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Posted 27 August 2009 - 06:32 AM

That's really awesome! The glob looks kind of strange floating there as a 2-D object, but that open cluster is spectacular. You just gave me an idea of one I want to try...

#23 Jeremy Perez

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Posted 27 August 2009 - 10:17 AM

These 3D sketches are amazing. Great work! Ferenc, your latest two sketches got my morning off to a great start. You managed to tilt M51, and the M34 cluster is mesmerizing. Granted, this does not depict observational reality, but it's still extremely cool. And if someone had the available time to get Hipparcos data on the stars in a view, it would be possible to convey a reasonable facsimile of what's actually going on. I hope to try it out on some of my deep sky sketches sometime.

In the meantime, I gave it a shot on a Jupiter observation from last night. There were three moons and two shadows gathered closely. Io was emerging from Jupiter's shadow, so I tucked it back, Europa and Ganymede were in front casting shadows, so I moved them forward (trying to move Ganymede outward the most). Shifting Ganymede's disc involved cloning it into a new spot and cloning out it's old position. I tried to make Jupiter appear round by using the Liquify filter with a huge, soft brush about 1.5X as wide as Jupiter to nudge the planet's face to the right. It seems to provide the right illusion...

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#24 Jef De Wit

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Posted 27 August 2009 - 01:24 PM

Rich, TenthEnemy, Starquake and Jeremy
Thanks a lot for all your creative 3D-work! I didn't expect that my simple question would have this result! Anyone 4D?

#25 kraterkid

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Posted 27 August 2009 - 02:13 PM

Jef, technically my fly over vids are 4D. They require time as well as the 3D model.

I must say that I'm so impressed with all the great work in 3D that I've seen posted here, the deep sky objects, planets and the Moon are just fabulous to see this way. Although as Jeremy points out, this is not as we see these in reality, 3D sketching can give us insights into the spacial relationships that are otherwise hidden in the 2D universe we see in the sky.

Anyone do a solar 3D? :question:






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