viking
Posts: 73
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Registered: 19 Feb 2006
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360 Panorama for the first time.
Posted: 19 Feb 2006 at 15:29 GMT
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Hi! Im very new here, just found the website and registerd myself on it. Great site with alot of info.
I have been assignd to take a few 360 multirows panoramas next month. The gear I having is a Nikon D200, Manfrotto/bogen tripod with the 303SPH panorama head and a few lenses. One of them is a mega expensive macro lens and the other one is a zoom lens with a focal lenght of 28-XX (poor memory). I have a budget where I can get almost the lens I want. I will also use realviz sticther for making the panorama.
I have read on a few page that calibration of the lens is needed. I dont realy understand that, maybe becaus english is not my first language. But calibrating is when locating the "nodal point" on the lens? And to do that I need to have the camera on the tripod, with the panhead and change the vertical and horizotal tilt? But how do I know how much to move it?
Is it hard to stitch it togheter? What is the hardest part?
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VRobject
Posts: 145
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Registered: 10 Feb 2005
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Re: 360 Panorama for the first time.
Posted: 19 Feb 2006 at 20:09 GMT
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Hi,
The Nikon D200 is a very good camera, no problems there. It’s recommended that you shoot RAW (not jpeg), there’s more dynamic range to extract, it’s easier to correct the chromatic aberration and to make lots of adjustments… and a 16bit lossless workflow can really improve the overall quality.
You choose the lens according to the required output resolution : a Nikon 10.5mm fisheye lens on a D200 can create a spherical pano at about 11000x5500 pixels, with only 6+2 shots, for example.
I don’t think you’ll have much use for the macro lens … and that 28-xx lens (42mm focal length, if you take into account the 1.5x crop factor of the camera) will require at least 4 rows x 14 images, plus nadir and zenith … so, you need a wide angle lens.
An 18mm lens (27mm equivalent) : 3 rows x 10 pics +z/n.
The Sigma 12-24mm (recommended for Realviz Stitcher, as opposed to the Nikon 12-24mm) : 2 rows x 8 pics +z/n.
I have read on a few page that calibration of the lens is needed
If you’re referring to Realviz Stitcher, it has an option called High Distortion/Calibrate … but that's not the same thing as the nodal point.
You can find more info here : www.panoguide.com/howto/panoramas/setup_panohead....
www.edb.utexas.edu/teachnet/QTVR/NodalPoint.htm
services.manfrotto.com/303SPH/main.php?cnt=howto
If you don’t want to trouble yourself with nodal point adjustments there’s always the 360Precision panoramic head www.360precision.com .
Is it hard to stitch it together? What is the hardest part?
It’s not that difficult, especially if have a sturdy tripod, a good pano head, the correct nodal point and a bit of know-how.
What kind of panoramas were you asked to produce ? … full 360°, for web/print, inside/outside ?
It’s better to start making some panoramas now, before the actual project, in order to get some experience You can use the 28mm lens and Stitcher to do some partial panos (mosaics).
If you run into problems we’re here. 
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viking
Posts: 73
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Registered: 19 Feb 2006
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 13:27 GMT
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Thank you alot for the reply!
I did a typo. Im going to work with the D100 camera, not D200. Sorry about that.
Im going to do Full 360° for webb usage. QTVR, but they want it in flash (swf or fla). Is there any good way to get flash panoramas? I've seen a few, but the quility on them have been a bit poor for my eyes. The quicktime thingy is alot better to me. But QT needs plug-ins. Im going to do both inside and outside.
I did a little QTVR panoram in my kitchen. With my 350D and a 28-75mm lens. Almost all lines where not alliged, more known as ghoosting. I did it handheld. i dont have the panhead here.
The panohead im going to use is the 303SPH and a Manfrotto tripod. Dont know the model number on the tripod.
Is it not possible to do a 360x180 panorama with a 28 mm lens? How do I know how many rows and picture I need? And how di I know how much overlapping
If I use a fisheye, Do i need to "defish" all the pictures before I stitch them in sticther?
again, thanks for the reply 
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VRobject
Posts: 145
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Registered: 10 Feb 2005
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 15:34 GMT
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You’re welcome
I’m not aware of any commercial full 360° Flash players, but Immervision has made one : immervision.com/immerv2/en/multimedia/multimedia_...
It’s possible to do a 360x180 panorama with a 28 mm lens, but this will probably require to shoot 4 or 5 rows x 15 pictures … are you sure you can process all those images ?
You need to defish only if you use Stitcher … PTGui, PTMac can stitch the images directly.
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viking
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 17:39 GMT
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Hehe. Why could I not process all those images?
75 pictures.
75 raw pictures = 8 GB.
Maybe not.
Is there no formula how to calculate how many picture that is needed to get a 360x180° with a special focal lenght? And how do I know that the whole plane is coverd by pictures?
This will be an hard job.
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John Houghton
Posts: 3487
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 18:46 GMT
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I don't know of a calculator for 360x180. One solution is to use PTGui's Panorama Editor window. Create a set of dummy images all containing the same simple pattern. Add them into PTGui and set the focal length. With output set to 360x180 equirectangular, place the images in rows semi-automatically using the fill yaw feature, allowing whatever overlap you require. As you increase the pitch, fewer images are needed. You can move the images individually into position if necessary. It's easy to see if there are any gaps.
John
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viking
Posts: 73
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Registered: 19 Feb 2006
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 19:59 GMT
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Thank for your reply.
But how should I know how many rows to use if I use 28 mm
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John Houghton
Posts: 3487
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 20:39 GMT
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You just slide the images up and down to give the amount of overlap you want. Their size will be adjusted according to the focal length. When they fill up the available space, you know how many are needed.
John
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viking
Posts: 73
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Registered: 19 Feb 2006
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 20:47 GMT
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So its not a something to add to the panhead? Lets say I want pictures with 50% overlap, how do I fix that?
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John Houghton
Posts: 3487
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 22:33 GMT
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The image positional parameters maintained by PTGui give you the angles of yaw (horizontal) and pitch (vertical). If your pano head is equipped with angular scales, then you will be able to set the settings you need. You can judge 50% overlap easily by eye. It doesn't have to be exact. This screenshot shows a possible layout of images being devised using the panorama editor window:
You will note how the rectangular images become distorted and spread out near the top of the frame.
John
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VRobject
Posts: 145
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 22:58 GMT
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It’s probably easier to put the camera on the pano head and take some test shots than using PTGui …
If you want 25% overlap for the middle row… you shoot 15 images, one every 24° (your pano head has this option).
… but, for the rows situated near the zenith and nadir you need less pictures.
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viking
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Registered: 19 Feb 2006
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Re: 360 Panorama for the first time.
Posted: 21 Feb 2006 at 23:16 GMT
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This will be the hardest assaigment I have had in all my life!
I just dont understand how I should know How to be 100% sure that I have all the picture I need to cover 360x180°?! Is there no math I can apply?
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VRobject
Posts: 145
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Re: 360 Panorama for the first time.
Posted: 22 Feb 2006 at 0:46 GMT
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There are some calculators, such as this one : www.worldserver.com/turk/quicktimevr/calculators.... , but there’s nothing for multi-row 360x180.
My advice: get a wider lens … 18mm should be ok- 3 rows (-45°, 0°, +45°) x 10 images (every 36°) … or a 10.5mm fisheye : 6+2.
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FourPiGuy
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Re: 360 Panorama for the first time.
Posted: 22 Feb 2006 at 1:13 GMT
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viking said: Is there no formula how to calculate how many picture that is needed to get a 360x180° with a special focal lenght?
For starters, you need to know what your horizontal and vertical fields of view are. For rectilinear lenses:
FOV = 2*ATAN(L/(2*D))
where L is the distance across the image sensor in the direction of interest (i.e. its width for HFOV, its height for VFOV) and D is the focal length of the lens.
For example, a 36mm x 24mm sensor (35mm film) will reduce to the following:
HFOV = 2*ATAN(18/D)
VFOV = 2*ATAN(12/D)
If you don't know your sensor's dimensions, use your camera's crop factor and use the resulting 35mm equivalent focal length with the preceding two formulae.
Once you know the VFOV and amount of overlap desired, it's fairly straightforward to calculate how many rows you'll need to span the 180 degrees.
The 360 degree horizontal coverage works the same way if the camera is not angled up or down (think cylindrical). It get a little messier for sphericals because, as John mentioned, the distance around a sphere at a given latitude is dependent on the pitch angle. The equatorial circumference is just a special case where the pitch is zero and the distance around is a maximum requiring the greatest number of shots for coverage.
With my A200 and wide angle converter, if I remember correctly, I took 8 shots at 0°, but needed only 6 shots at +/- 30°, even less at +/- 60°. And of course you only need one at +/- 90°!
Anyway, in practice, use the formulae to get you in the ballpark. Then go out and count the number of rows and images required by panning and tilting your camera in a practice run while paying attention to the overlap.
Oh, and don't forget that VFOV becomes HFOV (and vice versa) when shooting in portrait mode.
Gp
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viking
Posts: 73
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Registered: 19 Feb 2006
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Re: 360 Panorama for the first time.
Posted: 22 Feb 2006 at 10:58 GMT
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Im going to get the stuff from the work now. And test a little bit here at home. I have a 18mm canon lens as the widest. I hope it will work to start with.
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