What kind of lens does hugin call a Rokinon 8mm?

[Brandon]

I have a new fish eye lens and I do not know what to tell hugin it is.

It is a dead lens, so it does not have any exif data for hugin to look at so I need to put it in by hand. The lens is a

Rokinon HD8M-C 8mm f/3.5 HD Fisheye Lens with Removeable Hood for Canon DSLR 8-8mm, Fixed-Non-Zoom Lens

http://www.amazon.com/gp/product/B008X1C4IY/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1

The part that has me stumped is it a normal lens, circular fish eye, a full frame fish eye or something else? I am using it on a cannon rebel t5 if that makes any difference. It has a focal multiplier of 1.585x

[panostar]

On Thursday, October 16, 2014 8:18:12 PM UTC+1, Brandon wrote:

I have a new fish eye lens and I do not know what to tell hugin it is. 

On the Canon T5, the lens behaves as a full frame fisheye.  The focal length usually works out nearer 9mm than 8mm, but the optimizer will evaluate the correct hfov when you stitch a full 360x180 panorama. 

John

[David Benes]

Hi Brandon,

is seems, that it is the same lens as Samyang 8mm f/3.5 (except the removable hood).

That Samyang has stereographic projection.

Regards

David

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[Brandon]

On Thursday, October 16, 2014 1:02:34 PM UTC-7, David Benes wrote:Hi Brandon,

is seems, that it is the same lens as Samyang 8mm f/3.5 (except the removable hood).

That Samyang has stereographic projection.

Regards

David

On your advice I just tried a stereographic projection and re-optimized one of my projects and it looks great!  I had tried the other settings that I mentioned above and it never worked out. I was starting to worry that the lens would not work with hugin.

A big thanks, getting that right makes me a lot happier person :)

I still need to figure out how the correct lens parameters. The two projects that I just loaded and optimized are now doing very well. The only complainant is that the extreme edges are not quite lining up right. Hopefully a night of messing around I can get them corrected.

To shift the question a little bit, how does a person know what kind of projection is the correct one for their lens and or camera combo? I read everything there was with my lens and there was no mention of anything that would have lead me to think stereographic.

On the Canon T5, the lens behaves as a full frame fisheye.  The focal length usually works out nearer 9mm than 8mm, but the optimizer will evaluate the correct hfov when you stitch a full 360x180 panorama. 

John

 I was thinking the way you were and had been trying the various fisheye projections and it was not working. Maybe someone has some insight as to why it turns out to be a stereographic instead?

[jepz11]

On Friday, October 17, 2014 2:57:00 AM UTC+2, Brandon wrote:

On Thursday, October 16, 2014 1:02:34 PM UTC-7, David Benes wrote:Hi Brandon,

is seems, that it is the same lens as Samyang 8mm f/3.5 (except the removable hood).

That Samyang has stereographic projection.

Regards

David

On your advice I just tried a stereographic projection and re-optimized one of my projects and it looks great!  I had tried the other settings that I mentioned above and it never worked out. I was starting to worry that the lens would not work with hugin.

A big thanks, getting that right makes me a lot happier person :)

 
[...]

Glad you are :)
Thanks to you both for the info.

Can't help with the lens parameters as I'm just a Hugin beginner. But, an enthusiastic user.
A question, hope I don't hijack the thread by it.

Is it possible, using a fisheye lens on a camera reporting the correct exif data, to convert the (ugly) fish eye projection to equirectangular, rectangular or stereographic using Hugin?
Meaning, the way I make panorama's by a simple camera using many photo's could be done in a single shot?
Avoiding any parallax problems in one go..
Thanks,
Jan.

[panostar]

On Friday, October 17, 2014 1:57:00 AM UTC+1, Brandon wrote:

I was thinking the way you were and had been trying the various fisheye projections and it was not working. Maybe someone has some insight as to why it turns out to be a stereographic instead?

I owned a Falcon 8mm fisheye for a while (the same Samyang optics) and trying one of my projects with lens type full frame fisheye and also stereographic, I found almost no difference in their optimization reports (using the same set of control points).  I never had any difficulties stitching images using the full frame lens type, though stereographic ought to be preferable. It's interesting, therefore, that you were not able to get a satisfactory stitch using full frame or circular fisheye lens types. It would be nice to take a look at the images to see what's going on.

John