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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

The All 3D-Stereo Thread

"I watched Max Penner have two customized inputs into a Red LCD and I would wear 3-D glasses which were hanging on the camera."

I haven't liked the traditional projected 3d at all. Perhaps the glasses with two independent little screens would be the trick. But then, who needs a theater for that?

Also, check out this mirror rig:

http://www.youtube.com/watch?v=s4rGVztZqsM
 
Red will make 3d Stereoscopic easier to handle than anything else before.:red_bandana:
 
Ayoji said:
Red will make 3d Stereoscopic easier to handle than anything else before.:red_bandana:
Click to expand...
How so? Interocular distance a touch wide with two red bodys mounted side by side I'm informed.
 
accommodation depth clue

accommodation depth clue

cholo said:
There's a serious shortcoming I find with current 3D technology used in movies... Focusing.
In real life, when you experience something through your eyes, your point of interest determines the focus distance and as you jump from one thing to another, so does the focus. 3D movies however, either force focus at a certain distance, which makes you aware of the situation, breaking the "spell" of the movie experience; of forces everything into focus, making it feel unnatural. Ideally, there should be some kind of system that tracks your eye movement and brings the correct plane into focus as your eye wanders throughout a scene.
Another problem is lens flares. Since 3D is supposed to mimic a real life experience, lens flares are not a part of human vision, not to mention they look different for each camera, making for a very weird artifact. I was very aware of this when I watched U23D at my local IMAX screen. Great experience though :)
Click to expand...

I wrote a paper many years ago about how to make a 3D autostereoscopic display with "accommodation depth clue", in such a display the exit pupil is smaller than the iris of the eye, maybe 0.25mm, so when your eyes converge on a point in the 3D space they can also focus on that point, that does two things,

1) It lets you Accommodate (focus your lens) at the right distance. Your eyes "feel" how far things are away by how hard the mussels pull on the lens to focus, in standard 3D displays the lens focuses at one distance while the eyes converge at other distances, making for eyestrain and lower since of depth.

2) Being able to focus at different depths in the 3D space helps you perceive depth and isolate your point of interest from the background and forground, such as if you are looking at a bird in a bush you do not want the twigs in sharp focus since you are not converged on them. In 3D vision things that are converged on are also in focus, and all things not converged on are not in focus, and so the display type I wrote about makes 3D more like natural vision as well has having H/V paralax and look around, like a Hologram. I also went into ways to make the display brighter and how to reduce the bandwidth required without reducing image resolution.

The drawback of such displays is that they cannot be made to work(?) in a large theatre because of problems with the optics used and the ability to focus the exit pupils to less than 0.25mm. For smaller displays viewed closer than a few meters the results should be almost natural.
 
Seán_T said:
How so? Interocular distance a touch wide with two red bodys mounted side by side I'm informed.
Click to expand...

Your right. It was a statement of faith not based on facts. The fact is Red is on the forefront of the cinema digital revolution and that's why I have faith it will take on Stereoscopic Digital as well. :red_bandana:
 
Proceedings 747

Proceedings 747

Benni Diez said:
Is it published somewhere?
Click to expand...

SPIE proceedings 747 13-14 January 1987 Los Angeles CA Paper 747-04 "Estimating the performance of stereographic video displays, D.H. Hudgins Page 30" the editor added the Consultant title, that was not my choice.

Although I did not talk about accommodation in a previous paper it does talk about how to get a video display with H/V parallax, that is in Proceedings 367 August 26-27 1982 San Diego CA 367-09 "Transmission and storage bandwidth reduction for spatial image data associated with three-dimensional television systems with parallax, Daniel H. Hudgins, p. 68". Its the same idea, but resolution of the exit pupils and how you work out the details controls the amount of accommodation you can see, you sort of have to read between the lines in the papers, probably most people did not get what I was implying at the time from the few comments I got.

The 747-04 goes into using optics to reduce and select the exit pupil needed, a group of exit pupils would be needed for accommodation depth clue. Dr. Benton is dead now, but we talked about this subject at lunch twice, his papers about holographic stereograms are relevant to the subject.

Good quality optics are needed to get good results, otherwise things outside the plane of zero disparity will get softer in focus, as can be seen in some white light holograms. If you want to build a display like this let me know, it would cost something though in parts.
 
When will Reduser have a 3D Stereoscopic subcategory thread? Like, Shooting Red-Audio, Shot on Red, etc.
 
dali?

dali?

-two separate small monitors, each for one eye. Like those fancy cyberspace helmets.

so if i can somehow shoot two synced cams for 3d, i can play them on two monitors, and stick a board in between where one would place one's nose and watch?

I saw this at the salvador dali museum in france, and this guy had a painting for each eye and would separate vision with a board.

can't remember what color the board was. If anyone's tried this it could be cool for an installation...

t
 
I'm confused about the whole focus thing.

If a scene was photographed to have infinite depth of field and everything in the frame was in focus how is there a problem for the viewer? Cant you just choose what to put in focus by glancing at it?
 
Weston said:
I'm confused about the whole focus thing.

If a scene was photographed to have infinite depth of field and everything in the frame was in focus how is there a problem for the viewer? Cant you just choose what to put in focus by glancing at it?
Click to expand...

In the real world, you normally focus on the object you converge your eyes on. The blurring of out-of-focus objects depends on the real world distance!
When you watch 3D screenings, your eyes will have to focus on the screen. The images are still screened on a flat surface. So there is no altering of focus when they come nearer, only the convergence changes.
That's one reason why even the best 3D projection can be weary after some time. We're used to focus on the same objects we converge on. That does not happen with present 3D screening techniques.
Also try looking at two objects with only one eye, one very close and one very far away, and then alter your focus back and forth between them. Not that easy. And you'll recognize that the covered eye still tries to converge based on the focus.

So, no. If you film everything in focus, it will always be everything in focus. The best way is to set up the shots so that the region of most probable interest is in focus. And better make moderate use of depth blur.
I actually think that smaller chips are better for 3D, so the 2/3 scarlet could easily become THE 3D camera.
With the greater depth of field you can still converge on an object that's not exactly in focus and still be ok with it.
 
I didn't realize that. Thats disappointing.

So will there ever be a way to present infinate depth and complete focus?
 
Hey guys, a bit of an idea here. Maybe contact Jarred and see if this whole thread can get moved over to the REDUser Group area. I'm sure this discussion will go on and develop as 3D becomes a more acceptable viewing format. It may just be nice to have a pretty stable location for the thread......

Just an idea. Great read by the way.

Cheers,
Mark.
 
CG

CG

Weston said:
I didn't realize that. Thats disappointing.

So will there ever be a way to present infinate depth and complete focus?
Click to expand...

If you scan the whole scene with 3D scanners (LIDAR etc.) and then re-generate it with CG you can get infinite depth of field.

With optics the plane of focus is sharper than all other parts of the field of view, and as was pointed out your eyes feel distance by focusing on the point where they converge the two images on a point on the subject.

If you use a pin hole lens you cannot get high resolution on a small format sensor.

As I mentioned before here, I worked out how to make a display that gives you accommodation depth clue by subdividing the exit pupil in an autostereoscopic display, but it is not practical to build such a display for a large theatre.

You could have people in a theatre wearing a special type of VR helmit with extra electro optics that would let them accomidate and converge like in normal vision.

How you would capture the many views for such a display is a problem, but if you use capture to 3D simulation to multi-view rendering you can solve this in a way that is workable, or will be soon with computer power vs. price improvements.

In the case of multi-view (CG) rendering each of the many views each eye will be shown together has a kind of infinate depth of field, when the views go through the lens in your eye they are focused in a way that lets your eye select the plane of focus at any particular depth, as it would in normal vision.

[I was www.DANCAD3D.com but now go by real name...]
 
How you would capture the many views for such a display is a problem, but if you use capture to 3D simulation to multi-view rendering you can solve this in a way that is workable, or will be soon with computer power vs. price improvements.

In the case of multi-view (CG) rendering each of the many views each eye will be shown together has a kind of infinate depth of field, when the views go through the lens in your eye they are focused in a way that lets your eye select the plane of focus at any particular depth, as it would in normal vision.

[I was www.DANCAD3D.com but now go by real name...]
Click to expand...

Would using a plenoptic lens be a good way to accurately capture all possible planes of focus in live action filmmaking?
 
Lenslets

Lenslets

Weston said:
Would using a plenoptic lens be a good way to accurately capture all possible planes of focus in live action filmmaking?
Click to expand...

The lenslets have their own focus point, and if you stop them down much you get less resolution, so there is a limit to how deep the focus can be with this type of stereographic lens array, which is why I went with large lenses rather than micro lenses for some of the autostereoscopic displays I described. These sorts of micro lens camera have been around for a long time and can be reflex, you can take and view with the same micro lens array.

At some point the better way is to capture the wave front since the micro lens array limits the resolution.

Also the bandwidth for a micro lens array is too large since it captures all views not just the ones needed. You could drop the data that is not needed, but you do not know what data to drop in advance if you are recording the images for later VR playback with the viewer selecting the views.

If you use more gross methods to capture the scene and then CG just the views the viewer requires you reduce the number of views (per viewer) to maybe 100 to 400 rather than millions since you just need to cover the area of his pupils.

The 90,000 pixels in each sub-image is low resolution,

http://en.wikipedia.org/wiki/Plenoptic_camera

You could stop a normal lens down to that resolution and get more depth of field as well, you can also rack focus a fast lens and extract depth, this is just a parallel way of doing that rather than serial.

If you made a very large array like a 30 feet square or had the walls of the studio lined with such arrays (like on a dome or sphere walls surface) you might be able to capture 3D well enough to CG the actors. Maybe someday such parallel data could be processed?
 
Stereoscopic 617 would be compact if they made two lenses to fit on it.:pinch:
 
617 "realist"?

617 "realist"?

Joseph Ward said:
Stereoscopic 617 would be compact if they made two lenses to fit on it.:pinch:
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If you needed to adjust the eye spacing you might be able to add prisms?

http://en.wikipedia.org/wiki/Stereo_Realist

The Stereo Realist users have experence with this sort of set up, it is easy to move the lens board in and out to rack focus both lenses together.
 
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