DorinDXN
Posts: 1608
Location: Timisoara, Romania
Registered: 14 Nov 2006
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How to take stereo panoramas with Nodal Ninja 3
Posted: 15 Mar 2008 at 22:31 GMT
updated: 15 Mar 2008 at 22:53 GMT
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Hi, I want to post here how to take stereo panoramas with Nodal Ninja 3 panoramic head. (NN3)
This photo shows a regular use of NN3 for, say, 2D panoramas
if one use the T-adapter of NN3, (designed for mounted some off center mounting cameras) to have a 3 cm lateral shift of No Parallax Vertical Axis (NPVA) like in this photo where I marqued with red that 3 cm lateral shift
this become so the "right eye camera" and is used for taking the photos for right eye pano
Now the trick, if one rotate the NN3 with 180 degrees about its upper rotator and with another 180 degrees about its lower rotator the result is shown in this photo
this become so the "left eye camera", the camera is upsided/down but this doesn't matter.
Now the lateral shift of NPVA is 3cm in opposite direction
if one take a pano with right eye camera and then, after that double rotation, a pano with left eye camera, without moving the tripod, the setup acts like two camera setup but using only one at the time and the lower rotator of NN3 acts like "neck" of a panoramic viewer.
The total amount of the lateral shift of NPVA beetween left eye and right eye become so 3+3=6 cm close to human stereo sight.
Even if one uses fisheye lens which can assure a pano from only 3-4 photos, the number of photos must be around 10-12 for each pano to have a distributed parallax and the process of panos is more difficult than the regular panos because of that parallax, but can be done.
To see one of my cross-eye spherical pano made in this way one must use the free DevalVR plugin
www.devalvr.com/install only under Windows for now.
please use the arrow keys for rotating in a particular direction, left SHIFT and left CTRL for zoom in/zoom out.
dorin.devalvr.com/dxn_pano/crosseye_3/target_man_...
dorin.devalvr.com/dxn_pano/crosseye_4/pano.html
if interest is shown I'd love to discuss about this technique.
Dorin
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Pierre Gielen
Posts: 18
Location: Netherlands
Registered: 23 Jan 2008
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 16 Mar 2008 at 1:00 GMT
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DorinDXN said: the number of photos must be around 10-12 for each pano to have a distributed parallax
Hi Dorin,
Great experiment! I am going to try one of those myself, but why exactly does the number of photo's have to be 10-12? Would this mean that with my Nikkor 10.5mm (I normally shoot 6 photos around + zenith + nadir) I would need about 20 photo's?
And how do you synchronize the two panoramas for viewing? I haven't used the cross-eye technique yet myself, but I have made anaglyphs before (both with a sliding bar and with a Loreo lens). Which is nice, only you need cyan-magenta coloured glasses.
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DorinDXN
Posts: 1608
Location: Timisoara, Romania
Registered: 14 Nov 2006
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 16 Mar 2008 at 10:53 GMT
updated: 16 Mar 2008 at 11:06 GMT
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Hi Pierre,
I found that 10-12 photos are good for preserving the 3D along all 360 degrees so one take 10-12 photos with either 18mm on or Sigma 8mm on 1.6, in case of 18mm if one want spherical three rows are needed
So for the Nikkor 10.5 also 10-12 photos but pay attention on zenit shot, try to take two for each at 90 degrees of yaw appart or three at 120 degrees appart but at pitch just to cover the hole up, if 12+1Z+1N doesn't work.
About one year ago I published the first on anaglyph Cyan-Red on my web page like this
www.dxn.ro/dxn_pano.html?pano=anaglyph1
but from feedback from John Houghton and others the color experience isn't so pleasent, but is available in immersive fullscreen.
I will not insist in persuading here to see the panos in cross-eye if one can't and feel to be hurting or difficult, anyway with anyone I tried and I have the feedback seems that the effort is related only with the distance from the screen and there is a distance from which is no effort at all, once the way to see is found, the finding could be/ seems to be/ difficult as for me was impossible first day I tried as, somehow I belived that I need to cross the eye hard and somehow the 3d appear, then I found the method on concentration on a particular detail and all become natural and easy at certain distance from screen. Even the lateral 2 flat images can be hided with a piece of paper.
The benefit is true color.
The sync is posible in DevalVR for spherical pano and due to work of Ken in his java viewer too for cylindrical panos.
@Ken if you have NN3 you can produce your own cylindrical panos. Let me know if you need for more info about taking and stitching.
Dorin
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lbjohnik
Posts: 6
Location: Sweden
Registered: 10 Mar 2007
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 16 Mar 2008 at 20:38 GMT
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Hi,
Thank you for the excellent pictures showing the technique you are using for shoting tthe 3d-pictures!
I made a fast try this afternoon, but it turned out I had several problems stiching the pictures with PTGui. The main problem beeing the overlap of the pictures so straight line get hack/notch/cut (I don't know the exact English word):
This would be expected for the set-up since I'm adding a parallax problem. Your pictures doesn't show any sign of this, even with objects close to the camera. Do you have some suggestions how to work around it?
Regards,
Johan
P.S. My workflow for taking panorama pictures:
Canon 400D + Sigma 8mm f3,5. Nodal ninja 3. Shooting 4 shots around with 10 degress pointing downwards and one up.
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Mark Schuster
Posts: 676
Location: Welwyn Garden City, United Kingdom
Registered: 25 Jan 2006
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 17 Mar 2008 at 0:45 GMT
updated: 17 Mar 2008 at 0:47 GMT
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Dorin,
Just an idea. Could this be an alternative way to get the same results without having to check the viewfinder to ensure the camera is still pointing at the same place?
I can't test it because I don't have the same apparatus but my very rough estimate is it will permit a lateral shift of between 5.5 and 6.5 cm.
The large knurled knob will need to be changed to a smaller wing screw. I think there is one in the NN kit.
Mark
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DorinDXN
Posts: 1608
Location: Timisoara, Romania
Registered: 14 Nov 2006
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 17 Mar 2008 at 6:30 GMT
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lbjohnik said:
This would be expected for the set-up since I'm adding a parallax problem. Your pictures doesn't show any sign of this, even with objects close to the camera. Do you have some suggestions how to work around it?
Hi Johan,
Take 12 photos for left pano and 12 for right pano, if you use PTGui, in Create Panorama tab please select at layers : Blended and layers then over the stitched equi add as a layer the photo which contain that broken object/feature and so you can "move" the seam by retouching in your favorite graphic editor.
Dorin
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DorinDXN
Posts: 1608
Location: Timisoara, Romania
Registered: 14 Nov 2006
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 17 Mar 2008 at 6:46 GMT
updated: 17 Mar 2008 at 7:04 GMT
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Mark Schuster said: Dorin,
Just an idea. Could this be an alternative way to get the same results without having to check the viewfinder to ensure the camera is still pointing at the same place?
[img]
I can't test it because I don't have the same apparatus but my very rough estimate is it will permit a lateral shift of between 5.5 and 6.5 cm.
The large knurled knob will need to be changed to a smaller wing screw. I think there is one in the NN kit.
Mark, You don't need to check the viewfinder, also you don't need to shift anything at shooting session.
Just use it as I posted mean take the 12 photos for right eye pano with right eye camera then rotate on the upper rotator with 180 then on the lower rotator with 180 and take another set for left eye pano.
The alignment, i.e. to assure that the "cameras" will look in the same direction at panning will be done in PTgui or Hugin using both stitched equirectangulars.
Using T-adapter has the benefit of keeping the rail-stop as a quick refference but you can shift those 3 cm without T-adapter of course, but again shift at home, secure the vertical arm, and on the field only rotate.
It doesn't matter in which direction the shift is done, only to be at 3cm from the corect lower setting of NN3.
Tell me more about your aparatus to guide you how to make settings on it.
Dorin
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DorinDXN
Posts: 1608
Location: Timisoara, Romania
Registered: 14 Nov 2006
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 17 Mar 2008 at 7:12 GMT
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DorinDXN said: Take 12 photos for left pano and 12 for right pano, if you use PTGui, in Create Panorama tab please select at layers : Blended and layers then over the stitched equi add as a layer the photo which contain that broken object/feature and so you can "move" the seam by retouching in your favorite graphic editor.
please read
..then over the stitched equi add the layer of the photo which contain that broken object/feature.
along with the stitched equi, PTGui will produce another 12 equis/layers, one for each original photo, at those layers I'm reffering to be added over the stitched equi.
Dorin
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lbjohnik
Posts: 6
Location: Sweden
Registered: 10 Mar 2007
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 17 Mar 2008 at 20:51 GMT
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Hi,
Thanks once for great suggestions, Dorin! I've tried both 8 and 24 (!) pictures tonight. With the multitud of pictures and the "post processing a layered panorama" suggested by you and PTGui-tutorial
www.ptgui.com/examples/postprocessing/
I can now handle the problems with hack/notch/cut.
Can I ask two more questions, please, since you have taken this technique to perfection?
1. I have problems with some rotation in the panorama. Looking straight forward (same direction that first picture was taken) the right picture has a sligt counter-clockwise rotation and the left a clockwise rotation. Do you have the same experience? If you do, do you have a suggestion on what to do? If you dont, do you think there is something wrong with my setup?
2. For some reason when I have made my equirectangular pitures they are pointing in different direction. I mean that when I look at the center of your pictures (the place you get if you draw two diagonal lines in your pictures, sort of like a cross) both your pictures are looking at the same point. Theoreticly the right picture should be a little bit to the right and the left a little bit to the left, at least when you are working with normal stereo/3D-pictures. Do your pictures line up right away using PTgui or do you have to use "set center point" in the panorama editor of PTgui to get both pictures to have the same center-point? Would same centre point be better then "left sligt to left and right slight to the right"?
For Mark: I'll try your suggestion with the No Parallax Vertical Axis (NPVA) in a little while.
Regards,
Johan
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DorinDXN
Posts: 1608
Location: Timisoara, Romania
Registered: 14 Nov 2006
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 18 Mar 2008 at 8:31 GMT
updated: 18 Mar 2008 at 8:32 GMT
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Hi Johan, if your equis resulted are left.tif and right.tif then you need add both equis in a new PTGui or Hugin project and set the lens as equirectagular with HFoV=360 VFoV=180 then all the lens correction parameters set to 0 and at panorama settings select projection as equirectagular and at field of view 360(h) x180(v).
Now place widelly spreaded control points on distant from camera features then at the optimzer in advanced mode optimize only y,p,r for the right.tif then at Create panorama check at include images only 'Image 1' which coresponds to right and generate a new right_o.tif at the same size in pixels.
The stereo cross-eye panorama will conssist then in left.tif and right_o.tif.
If you use Hugin, use the latest stable version not the very last beta as it has a bug when add equirectangulars images as source.
Because is no shift with No Parallax Horisontal Axis in (NPVH) of NN3 the horizon line must be the same in both left and right pano, pay attention to that.
Dorin
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moto
Posts: 9
Location: Gurgaon, India
Registered: 24 Apr 2008
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 24 Apr 2008 at 15:58 GMT
updated: 24 Apr 2008 at 16:13 GMT
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Nice technique Dorin. I have been into pano photo for about 4 years now, and am just getting started in stereo pano. I have the bogen manfrotto spherical pano head with additional components for accurate, and consistent camera positioning.
i was thinking i was going to have to use the various sliders to move the camera after i finish each pano, or perhaps even every shot if there are moving objects in scene. your technique is simple and ingenious. wish i would have thought of it lol.
anyway, thanks for the tips. in return, i feel obliged to share a tip of my own for you and the other guys/gals reading this forum.
you already touched on the fact that fisheye lenses make for more difficult parallax error problems. i would like to expand on that tho. with normal stitched panoramas, parallax is a bad thing, to be avoided at any cost (yes, it costs alot to avoid parallax lol). however, with stereo stitched panos, you actually want/need the parallax. this is what creates the stereo 3d affect after all.
i have experimented using various techniques, equipment, and camera settings. what worked best is using a long local length (85mm + the 1.6x sensor crop factor = 136mm effective focal length). i normally overlap by 1/3 frame, but in this case, use 1/2 to 2/3. Don't even consider shooting in RAW (which i normally ALWAYS do), as the total pano, especially if you are using bracketed images for hdr, will take hundreds of shots to complete a full 360x180 requiring multiple gigabytes of storage, and will be impossible to process. instead, i would recommend picking up a good gray card. www.whibal.com/ get the big one. use this to set a custom white balance, then shoot in medium resolution, low compression jpg. this will allow thousands of pics on an average memory card.
for those who have used autopano before www.autopano.net , and think of it as a 'toy app', its really not. if you dig into its engine, its actually a very powerful and efficient tool. and with recent versions, it has nearly unlimited power via its control point exporter that allows integration with pt software.
anyway, whether you use a program like ptgui (best imo) www.ptgui.com or something like autopano, as long as your scene has lots of static and unique texture in it, modern versions of the programs should handle the massive number of photos just fine, and stitch them nearly perfectly, with no parallax errors.
the key here is the long focal length. parallax errors get worse as you move away from the center axis, thats why fisheye lenses have such bad problems with parallax errors. but as long as you are shooting from a good tripod, with your nodal point centered in all axis except side to side, you shouldnt have any problem stitching together the pano using automated tools, if you stick with a long lens.
now, going with a longer focal length, you will have to worry a bit more about your focusing. i hope you are all already quite aware of the concept of hyperfocal distance. if not, google it. here's a nice lil tool that allows you to print out a hfd chart to take along with you on your shoots www.dofmaster.com/charts.html don't attempt to keep EVERYTHING in focus with maxed aperture, unless the entire scene has exceptionally good bright mid-day sunlight. as long as you stick to your hfd chart, you can keep the infinite horizon in focus, and still be good at about 30 feet or so. the areas under your tripod and directly around will not be in perfect focus, unless you refocus for nearfield (always gotta be careful when doing this, because the closer you focus, the smaller your dof). it can create ghosting really easily and create stitching problems. anyway, a soft focus under the tripod is usually fine, as it helps to soften the nearly impossible to avoid alignment errors when taking that last vertical shot. actually, if anyone has tips on how to do under the tripod shots easily and accurately, i'd like to hear about it.
just remember, this technique will not work (by itself) for the sky. not to worry tho. ive actually given up attempting to shoot the sky in the same pano. i only shoot up the horizon till i hit all the land, then switch to a fisheye to shoot the sky, and merge the two with image editing apps.
btw, as you can probably tell, im nutts about this stuff, and a research junkie, and have tons of photo equipment, and have done many many trial/error experiements. so if anyone wishes to learn more from my mistakes, reply to post or shoot me an email. johnmatulis@gmail.com
oh, and heres one of my most recent panos. i havent finished the spherical version yet, this ones about 360x120. im workin on a new website to show off more of my stuff. www.john.matulis.net/photography/panos/hawaii/sta...
one last thing, www.colorcode3d.com/whatis/index.htm awesome. havent tried yet yet, but thats my next move. ive always liked the panoguide forums, even tho i havent been an active contributer. but now that ive got some good experience under my belt, and especially since im bustin into the stereo stuff, i figured id get more active here to share knowledge and experience.
-moto
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John Houghton
Posts: 2095
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 25 Apr 2008 at 6:03 GMT
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moto said: Oh, and heres one of my most recent panos. i havent finished the spherical version yet, this ones about 360x120.
Moto, Nice panorama, but it would look a lot better if you were to centralise the horizon vertically in the image that you give to the QTVR generator. You wouldn't then get the bowl type distortion on the distant plain.
John
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moto
Posts: 9
Location: Gurgaon, India
Registered: 24 Apr 2008
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Re: How to take stereo panoramas with Nodal Ninja 3
Posted: 25 Apr 2008 at 9:23 GMT
updated: 25 Apr 2008 at 9:24 GMT
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i'll rework it when putting together the 360x180 version. but if i remember, i did center it within 1 degree. i took another look at it, and think what looks to be bowl distortion is actually mountains that just happen to make it have that affect. i really wish i would have had time to do this one hdr, but i was shooting with a fuji s2 which is very very slow, and my friends were kind enough to sit there and wait the half hour it took to get setup and take the pic.
oh, and you also got to remember i took the photo more than a half mile up. thats why the sealevel horizon is so far down.
-moto
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