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Thread: More on the Yasuhara Madoka 180

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thomash2

Posts: 154
Location: Germany
Registered: 19 Dec 2009
Re: More on the Yasuhara Madoka 180
Posted: 18 Jul 2012 at 14:18 GMT
updated: 18 Jul 2012 at 14:19 GMT
I have the sample lens with me. There are initially some problems with stitching in PTGui, but it comes down to how you do it. Auto align works sometimes, sometimes not.

When I get problems, I tend to generate the control points between each set of adjacent images, instead of all at the same time. Then optimize. Heavy lens shift needs to be on. PTGui tends to change it back to "Medium" when you use auto align.
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enbilaman

Posts: 148
Location:
Registered: 3 Mar 2006
Re: More on the Yasuhara Madoka 180
Posted: 21 Jul 2012 at 10:01 GMT

enbilaman said:

PTGui handles "pure Orthographic" circular images without any problem: stitching four images is easy to do and the output is accurate but it cannot cope with the extreme peripheral few pixels of the image (actually **no** software can perform such a feat because the required and hefty interpolation is hampered in this heavily compressed annular region).
This fact is very easy to verify by inputting 4 adequate such "synthetic" images that you can output from Flexify 2 for instance. Note that AutoPano Giga 3.0 a1 can now also provide such Ortographic material but... not as easily as Flexify 2 can.
Michel

Experimenting more thoroughly by using only three instead of four images, all of them of pure and ideal Orthographic projection.

Under these conditions, PTGui is unable to auto-detect any CP. Strong manual assistance by the user is thus required and it is eventually tricky to finally get an error-free output panorama. It's imperative to place spread Control Points very close (few pixels) from the edge of the image... where the compression is so heavy that it is hardly possible to visually recognize a faint detail of the scene to create valid pairs of CP.

Conclusion:
a) Stitching four "real" images with inevitable light fall-off and increasing softness near the edge of the image is most probably a challenge... and Jook is right!
b) Going from four to three source images (ideal and synthetic) is already crossing the threshold from a stable to a chaotic regime of the detection/optimization for warping algorithm(s). Stability of the optimization requires much more overlap area in adjacent images that usual to keep the stitching process easy to manage. This is logically not the case with Stereographic projection for instance.
Is Orthographic projection a pano-photographic dead-end?

Michel
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John Houghton

Posts: 3935
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: More on the Yasuhara Madoka 180
Posted: 21 Jul 2012 at 10:50 GMT

enbilaman said:

Under these conditions, PTGui is unable to auto-detect any CP. Strong manual assistance by the user is thus required and it is eventually tricky to finally get an error-free output panorama.

Michel, Having got an error free panorama, I assume using the project file as a template for subsequent projects would help. Does the "generate control points here" function then manage to generate any points?

John
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DorinDXN

Posts: 3116
Location: Timisoara, Romania
Registered: 14 Nov 2006
Re: More on the Yasuhara Madoka 180
Posted: 21 Jul 2012 at 11:01 GMT
updated: 21 Jul 2012 at 11:17 GMT
We need a better PTGui, in which the CP to be in equirectangulars, i.e. internally PTgui should remap the input images to equirectangular using an initial set of lens parametters and the CP to be gnerated on equirectangulars then the optimisation to improve the lens parameters, so on.. In short both automatically and by the user, the CP will be set/adjusted on equirectangulars, but I'm sure you got the picture.

cheers,
Dorin
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enbilaman

Posts: 148
Location:
Registered: 3 Mar 2006
Re: More on the Yasuhara Madoka 180
Posted: 21 Jul 2012 at 13:59 GMT
updated: 21 Jul 2012 at 14:13 GMT

John Houghton said:

enbilaman said:

Under these conditions, PTGui is unable to auto-detect any CP. Strong manual assistance by the user is thus required and it is eventually tricky to finally get an error-free output panorama.
Michel, Having got an error free panorama, I assume using the project file as a template for subsequent projects would help.

Yes John, I must assume that the template might definitely help with real-world images but I can't swear... while it works of course perfectly with another new set of "perfect" orthographic images.

John Houghton said:

Does the "generate control points here" function then manage to generate any points?

Yes it does.
Furthermore, I should have said that without template but after having given a sufficient number of CP to PTGui and when it begins at last to converge quite satisfactorily, then the "generate control points here" function works perfect and the rest of the refining process becomes a treat from this point on!

Michel
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DemonDuck

Posts: 418
Location:
Registered: 10 Mar 2011
Re: More on the Yasuhara Madoka 180
Posted: 21 Jul 2012 at 16:34 GMT
updated: 21 Jul 2012 at 16:36 GMT
Here's a page that summarizes various projections including the orthographic projection.

www.progonos.com/furuti/MapProj/Dither/ProjAz/pro...

As you see, the orthographic projection has it's viewpoint at infinity so all rays to the scene are parallel. Which means that the rays near the edge are nearly tangent to the surface which means that a small (1 pixel) move of the viewpoint will move the ray a large distance across the surface which results in the compression you see.

That's lost pixels that are gone forever. Any stitching and blending at the edges will always be problematic with that projection.

If I was shooting with the Madoka, I'd do an inverted tetrahedron or inverted pyramid pattern with 3 or 4 around tilted up significantly and one down all with generous crops. The center of that lens looks sharp, the edges are never going to work.
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PeterWong

Posts: 10
Location: Hong Kong
Registered: 18 Oct 2012
Re: More on the Yasuhara Madoka 180
Posted: 18 Oct 2012 at 17:10 GMT
Hi, I am an amateur panorama photographer. I take handheld panorama most of the time when I travel. I use a panohead if the situation allows. My old gear was a Nikon Coolpix P5100 with FC-E8. Recently I bought a Madoka 180 to go with the Nex.
Until they come up with a better stitcher that will handle the Madoka well, I have deviced the following unorthodox solution.

1. Take 4 shots around dipping down 15 degrees to cover the nadir with good resolution. (The obstruction of the panohead will be kept to the minimum in the end.)
2. Take 1 shot for the top, zenith.
3. Box the shots in tight squares. (the sensor is a bit off centre as usual.)
4. Defish the shots, so that the orthographic looks similar to the stereographic. (e.g. PTLens fisheye distortion by the value of 117. Vignette correction is also possible.)
5. PTGui stitches the 5 shots automatically with no problem.

Here are 2 examples:

6 shots Handheld:
210.0.215.204/peterwong/panorama/PlazaHollywood/p...
5 shots with Panohead:
210.0.215.204/peterwong/panorama/ForumCourt/camer...

Hong Kong Eyes:
home.netvigator.com/~wongpete/panorama
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PeterWong

Posts: 10
Location: Hong Kong
Registered: 18 Oct 2012
Re: More on the Yasuhara Madoka 180
Posted: 18 Oct 2012 at 17:15 GMT
updated: 18 Oct 2012 at 17:32 GMT
Sorry for double posting.

Hong Kong Eyes:
home.netvigator.com/~wongpete/panorama
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DemonDuck

Posts: 418
Location:
Registered: 10 Mar 2011
Re: More on the Yasuhara Madoka 180
Posted: 18 Oct 2012 at 17:40 GMT
The Madoka is a sharp lens. But the projection means you have to shoot 4-6 around which cancels the advantage of using a circular fisheye. That's frustrating. I hope they change the projection to a more normal projection so that 2-3 around can be easily stitched.

There's a small flaw in the PanoHollywood below the doorway in the light brown floor tile between the two arcs.

There's a small flaw in the ForumCourt up where the aluminum strips cross.
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PeterWong

Posts: 10
Location: Hong Kong
Registered: 18 Oct 2012
Re: More on the Yasuhara Madoka 180
Posted: 19 Oct 2012 at 16:00 GMT
Hi, I have deviced the following unorthodox solution. It works for me until they come up with a better stitcher that will handle the Madoka satisfactorily.

1. Take 4 shots around dipping down 15 degrees to cover the nadir with good resolution. (The obstruction of the panohead will be kept to the minimum in the end.)
2. Take 1 more shot for the top, zenith.
3. Box the shots in tight squares. (the sensor is a bit off centre as usual.)
4. Defish the shots, so that the orthographic looks similar to the stereographic. (e.g. PTLens fisheye distortion by the value of 117. Vignette correction is also possible.)
5. PTGui stitches the 5 shots automatically with no problem.

Here are 2 examples:

6 shots Handheld:
210.0.215.204/peterwong/panorama/PlazaHollywood/p...
5 shots with Panohead:
210.0.215.204/peterwong/panorama/ForumCourt/camer...


Peter Wong
I am an enthusiast panorama photographer. I take handheld panorama most of the time when I travel. I use a panohead if the situation allows. My old gear was a Nikon Coolpix P5100 with FC-E8. Recently I bought a Madoka 180 to go with the NEX.

Hong Kong Eyes:
home.netvigator.com/~wongpete/panorama
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PeterWong

Posts: 10
Location: Hong Kong
Registered: 18 Oct 2012
Re: More on the Yasuhara Madoka 180
Posted: 19 Oct 2012 at 17:24 GMT
I have made available for download the photos of the second panorama I posted last time.
The files are compressed for Web with factor 7, I hope the quality is still good.
Shots 01-05 are centered and defished such that orthographic appearance is changed to look like stereographic.













PTGui will align the 5 shots with a breeze. It is nearly perfect if you look close enough.

210.0.215.204/peterwong/panorama/ForumCourt/camer...


Peter Wong
Hong Kong Eyes:
home.netvigator.com/~wongpete/panorama
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John Houghton

Posts: 3935
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: More on the Yasuhara Madoka 180
Posted: 20 Oct 2012 at 8:58 GMT
Peter kindly posted copies of the original images together with the above remapped images on the PTGui forum. Both sets gave similar optimization results with quite high average control point distances (>3). The nadir suggests that the setup of the panorama head could be improved and this may be responsible for the minor stitching errors.

John
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Smooth

Posts: 4310
Location: Mount Panorama, Australia
Registered: 21 Jul 2004
Re: More on the Yasuhara Madoka 180
Posted: 20 Oct 2012 at 11:42 GMT
I stitched the image set 1 to 5 as listed. It wasn't an easy stitch but came together with some manual help.

The images are not processed very well, being shot at ISO 1600 doesn't help. The lower rail (NPP) setting is out quite a bit making things more difficult.

I see no reason to change projection. My tests with my own images from Sony NEX 5N and Madoka 180 stitch pretty easily. But outside of the lens quality on Chromatic Aberration it offers nothing compared to the modified Samyang MFT 7.5mm Fisheye.

I personally wouldn't recommend this lens to anybody. Far better options exist. I can see why Peter has upgraded from the FC-E9. It is an improvement, but with a little more thought and effort a better alternative could and should have been chosen.

Regards, Smooth cool
www.omnipix.com.au
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PeterWong

Posts: 10
Location: Hong Kong
Registered: 18 Oct 2012
Re: More on the Yasuhara Madoka 180
Posted: 20 Oct 2012 at 15:32 GMT
Hi, I have deviced the following unorthodox solution. It works for me until they come up with a better stitcher that will handle the Madoka 180 satisfactorily.

1. Take 4 shots around dipping down 15 degrees to cover the nadir with good resolution. (The obstruction of the panohead will be kept to the minimum in the end.)
2. Take 1 more shot for the top, zenith.
3. Box the shots in tight squares. (the sensor is a bit off centre as usual.)
4. Defish the shots, so that the orthographic looks similar to the stereographic. (e.g. PTLens fisheye distortion by the value of 117. Vignette correction is also possible.)
5. PTGui stitches the 5 shots automatically with no problem.

Here are 2 examples:

6 shots Handheld:
210.0.215.204/peterwong/panorama/PlazaHollywood/p...
5 shots with Panohead:
210.0.215.204/peterwong/panorama/ForumCourt/camer...


Peter Wong
I am an enthusiast panorama photographer. I take handheld panorama most of the time when I travel. I use a panohead if the situation allows. My old gear was a Nikon Coolpix P5100 with FC-E8. Recently I bought a Madoka 180 to go with the NEX.

Hong Kong Eyes:
home.netvigator.com/~wongpete/panorama
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Smooth

Posts: 4310
Location: Mount Panorama, Australia
Registered: 21 Jul 2004
Re: More on the Yasuhara Madoka 180
Posted: 20 Oct 2012 at 15:36 GMT
Yes, we got that the first time you posted it.
Why are you posting it again?

The very first thing you need to do is find the NPP correctly.

Regards, Smooth cool
www.omnipix.com.au
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