[ptx] HFOV, focal distance...

[Didier Hérisson]

Le Mercredi 1 Juin 2005 21:23, manouchk a écrit :
> Le Lundi 30 Mai 2005 08:55, Emmanuel a écrit :
> > Hi,
> >
> > I'd like to know if providing a good value of the HFOV is sufficient to
> > do a good stitching in hugin or if it is needed to adjust well the focal
> > length and cropping ?
>
> As noone seems to know the answer of my previous question, I ask my
> question in another way, what is the cropping factor?
>

Isn't it the ratio between the CCD and a 35mm detector? In the case of reflex 
(SLR?) cameras, people think about focales length instead of HFOV, with the 
35mm standard size in mind. My guess is, HFOV is calculated from focal length 
by Hugin, assuming a standard 24*36mm detector. 
If you know the '35mm equivalent' of your focal length, just put it as focal 
length and a cropping factor of 1.

> I have other questions is it possible to optimize HFOV in a 360° pano in
> hugin? If yes how?

I think so, but don't know enough about hugin/Panotools... Anyway, you can 
find in the plf version changelog:
Changelog :
* lun 28 mar 2005 12:00:00 CEST Couriousous <couriousous at mandrake.org> 
2.7.0.9-1mdk

- Add switch to enable big FOV ( disabled by default )
- New release

For big FOV, the algorithm is protected by some patent... Even if it's 
completely arbitrary!

>
> The HFOV of my camera (of poor guy) is a olympus C40 zoom if anyone can
> help me for HFOV, cropping etc..?
>
> Ultimate questions
>
> Is it possible to shoot a pano using photo taken the one in "landscape"
> orientation (for sky) and the other in "portrait" orientation ? I tried and
> optimizing didn't worked?

Help the optimizer by putting them manually with good orientation. Fit with 
too many parameters are full of local minima, you should not start from too 
far (in the configurations space ;) )

Didier