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Thread: More on the Yasuhara Madoka 180

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HalfPint

Posts: 81
Location:
Registered: 19 Nov 2007
Re: More on the Yasuhara Madoka 180
Posted: 29 Dec 2012 at 23:23 GMT
updated: 29 Dec 2012 at 23:52 GMT
Madoka on Olympus OM-D - set of sample images (50MB):
www.oldie-werkstatt.de/university.zip

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enbilaman

Posts: 148
Location:
Registered: 3 Mar 2006
Re: More on the Yasuhara Madoka 180
Posted: 1 Jan 2013 at 9:45 GMT
Thanks for sharing this rare photographic resource with us. Your pre-processing with Lightroom 4 was very good.

I've tried these images and thus learnt a bit more about the weird projection of this new lens.
When properly set in auto-align mode, PTGui and APG are able to give a good output but they both require intervention from the user for a better panorama. A bug is hampering Hugin (2012.0.0) from correctly warping this type of source images but I have been told that it has been fixed before a next release.

The lower borderline of the image circle is slightly but obviously dissymmetrical from left to right, most probably because of the intrusion of some lens ring support or of a camera supporting arm. Could you tell us a bit more about your pano-gear set-up?

Best regards,
and happy new year to all!

Michel
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HalfPint

Posts: 81
Location:
Registered: 19 Nov 2007
Re: More on the Yasuhara Madoka 180
Posted: 4 Jan 2013 at 19:53 GMT
Hello Michel,

the lower borderline non-symmetry might have it´s reason in the replaced mount (e mount to mft mount machined from an mft-to-something-adapter). I´ll try to align it a bit more careful asap.


Setup was a modified NN3 with T-adapter, lens ring might be a bit tricky for mft.


Regards HalfPint
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enbilaman

Posts: 148
Location:
Registered: 3 Mar 2006
Re: More on the Yasuhara Madoka 180
Posted: 4 Jan 2013 at 22:20 GMT

HalfPint said:

Hello Michel,

(...)

Setup was a modified NN3 with T-adapter, lens ring might be a bit tricky for mft.

Regards HalfPint


Looking at the last photo: the base and the lower part of the black vertical arm of the NN3 head is the sole reason.
I could have guessed it by myself...

Michel
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Nick Fan
[NodalNinja]

Posts: 770
Location: Hong Kong
Registered: 26 May 2006
Re: More on the Yasuhara Madoka 180
Posted: 5 Jan 2013 at 16:39 GMT

HalfPint said:


Hi HalfPint,
This lens is indeed better suited for MFT. Too bad the designer did not allow for this. If they made an easy swappable MFT mount for it, it would have been perfect.
Do you need to cut away anything from the lens for the modification? Can you show more on your mod?


Nick
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HalfPint

Posts: 81
Location:
Registered: 19 Nov 2007
Re: More on the Yasuhara Madoka 180
Posted: 5 Jan 2013 at 21:39 GMT
updated: 5 Jan 2013 at 22:02 GMT
Hi Nick,

it was just a simple replacement of the e-mount by a homemade mft-mount (same thickness). The difference in flange focal distance can be adjusted inthe lens. There was no machining required at the lens.
Focus and aperture work as they worked before.

Yasuhara planned/plans a mft version of the Madoka, so of course the designer allowed both. That was my strong guess which made me buy this lens blind for the modification.

Regards HalfPint
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Nick Fan
[NodalNinja]

Posts: 770
Location: Hong Kong
Registered: 26 May 2006
Re: More on the Yasuhara Madoka 180
Posted: 6 Jan 2013 at 11:27 GMT
updated: 6 Jan 2013 at 11:32 GMT
Hi HalfPint,

Thanks for the info. That is a good new. Now I need to open up my lens. smile I wonder if they change the design after the release. I asked them specifically about mount replacement when I reserved the lens before release.


Dear Nick Fan,

> I want to know if you will have the SAME lens for micro 4/3 mount? I
> imagine the image circle will be cropped in m43. and that is what I want
> for making panoramas. using more sensor area for higher resolution.

I understand what you say.

We are now trying to use other optical system in MADOKA(M).
Of course it is to keep "circle" fisheye.
For VR use, as you say, we don't have to keep "circle".
But most of the users need circle picture in circle fisheye lens.

The flange back of SONY NEX is shorter than micro 4/3.
So we cannot attach MADOKA(E) by using adapers.

I understand what VR photographers want.
I will feed back your opinion to or next products.


Best Regards.

-----------------------------------
Shin Yasuhara




Dear Nick Fan,

> Thanks for your reply. Is the rear mount removable?

Yes. you can remove it easily.
But if you will attach MADOKA(E) to micro 4/3,
you have to cut the aperture ring not only to remove the mount.
So we cannot encourage it.

As for the optical element, it will not interfere micro 4/3 cameras.


Madoka means circle in Japanese, so the same lens with MFT mount won't be a Madoka lens again.

Nick
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Wim Koornneef

Posts: 119
Location: Ouddorp, Netherlands
Registered: 15 Nov 2007
Re: More on the Yasuhara Madoka 180
Posted: 6 Jan 2013 at 15:03 GMT
updated: 6 Jan 2013 at 15:12 GMT
@ HalfPint, thanks for sharing the example images.

@ All, I optimized the images in PTGui and after adding manually some CP's I settled with a CP max error of 3 px.

The reason I can't get a better result is probably because the lens correction parameters are huge compared to other fisheye lenses. I agree with Michel that this lens has a weird projection but luckily despite this it is a useful lens.

PTGui is calculating a FOV of 195 degree but I doubt this is true, probably this is a side effect of the weird projection.

The result of this weird projection can be seen in the star shaped seems in the grass in nadir, the grass is pointing in different directions on both sides of the seems indicating a bad lens correction at the circular edge.

In case you have problems with optimizing, here is my PTGui template,
www.dmmdh.nl/forum_images/ptgui_university.pts

BTW, I noticed a nasty moire issue in the pano in the box in front of the largest building, I think this has nothing to do with the lens but only with the camera, I suspect most digital cameras will show the same moire.

Wim
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John Houghton

Posts: 3935
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: More on the Yasuhara Madoka 180
Posted: 6 Jan 2013 at 17:38 GMT
I ignored the very poor outer edge of the image circle by setting a crop circle with an fov of 160°. The lens parameters are then somewhat less frightening at about half those in Wim's project file. The control points are more readily generated when the lens and crop parameters are initially set via a template - such as my project file at:

www.ge.tt/7R3uXpU/v/0

John
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enbilaman

Posts: 148
Location:
Registered: 3 Mar 2006
Re: More on the Yasuhara Madoka 180
Posted: 9 Jan 2013 at 10:34 GMT
One other way than cropping the image circle and yet to get more reasonable lens correction parameters (as well as more stable optimization algorithms) is in the software dialog to set the input image to a more suitable fisheye lens projection!
But both PTGui and Autopano Pro restrict to Equidistance as the sole "Ideal" fisheye projection as it has been the tradition since PanoTools. Thus both Stereographic and Orthographic projections strongly challenge the process and also sometimes the computational stability.
Hugin now allows the user to select the input fisheye image to be corrected with respect to one of the four classical projections (i.e. stereographic, equidistance, equal area or orthographic among many others).
Unfortunately, a nasty bug is affecting the Orthographic branch of Hugin 2012.0.0. I have been told it to be now fixed and that we should wait for a next release...

Michel
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