Hi,

Shows what happens when one assumes!  Since you have a full frame body, your
overlap is about 44%.  That is pretty good.  You probably don't need to add
more images to help your cause.  FYI, I shoot with an 8mm sigma on either a
350D or 40D.  Shooting 6 pictures at 60 degrees gives me around 47%
overlap.  If you are confident with your a,b,c parameters that's fine,
however you may want to try optimizing them as well if optimizing  the 'v'
parameter doesn't help.

I am hoping you see an improvement optimizing the 'v' parameter.  Not being
able to stitch across the 360 boundary, really sounds like adjusting 'v'
parameter should help.

Best Regards,

- Gerry


On Mon, May 25, 2009 at 8:22 PM, slaterson
<[email protected]>wrote:

>
> i was optimizing for the y, p & r.  i have a, b & c parameters for my
> lens, so i wasn't optimizing for them.  i will try this again,
> optimizing for 'v' as well.
>
> i realize this isn't easy, especially after serveral attempts,
> including taking many sets of photos. :)  i had a feeling it would be
> a little easier, though, to be honest.  after looking at several sets
> of photos i have taken with this setup, i think i've got it dialed in
> parallax wise within a few pixels between shots, not sure how to get
> it better.  i am also using the longest lens i have available, i will
> likely rent a 15mm fisheye soon and try with that.
>
> i forgot to add that i am not using a cropped body.  i'm using a canon
> 5d body, at 24mm, the hfov is 53 degrees, so i think i am ok with
> overlap.  i initially tried taking shots at 20 degree steps, however
> this produced so many images it was difficult to work with and
> obviously very time consuming.  how much overlap should there be to
> get a good set of 'automatic' control points as a starting point?
>
> thanks!
> slate
>
>
>
> On May 25, 6:04 pm, Gerry Patterson <[email protected]> wrote:
> >  Hello,
> >
> > This may seem a silly question, but what parameters are you optimizing?
> > Since you have a full 360 around, you should also be able to optimize 'v'
> as
> > well, which might help.
> >
> > Keep in mind, what you are doing is hard. :-)  Taking a full spherical
> pano
> > inside a room with that long of a lens means you have to be dead-on with
> > your measurements to avoid paralax.   Much more difficult that stitching
> a
> > pano of objects far, far away.  (I had problems like this too, it just
> took
> > me a while to understand what I needed to try to fix it.  Once I got the
> > hang of it, it wasn't bad).
> >
> > Based on what you have said in your e-mail and my assumption that you are
> > working with a cropped body, your field of view in portrait mode (you are
> > using a nodal ninja which mounts the camera vertical) is about 34
> degrees.
> > 12 images around doesn't give you much overlap (14%).  I may be wrong
> here
> > but am guessing all of your control points are near the edges of the
> > images.  Can you switch to a different detent disc to give you more
> images
> > and increase the overlap?  This way you can have a more widely spaced set
> of
> > control points to pass to the optimzer.  It has been said here that it
> isn't
> > the quantity of the control points, its the quality.
> >
> > For the time being I would also consider dropping down to 8bit tiffs
> until
> > you get this sorted out.
> >
> > Best Regards,
> >
> > - Gerry
> >
> > On Mon, May 25, 2009 at 7:37 PM, slaterson
> > <[email protected]>wrote:
> >
> >
> >
> > > i recently got a pano head (a nodal ninja) and i'm having all sorts of
> > > trouble with seams in my panos.  i have simplified my image set in an
> > > attempt to isolate the problem, not that i think i have the problem
> > > identified i'm not sure how to fix it.
> >
> > > i took a set of photos to make a 360x180 of my living room.  the
> > > photos were taken at a focal length of 24mm, 30 degree steps around
> > > the vertical axis and 30 degrees around the horizontal, for a total of
> > > 60 images.  when stitching the entire set i was getting a lot of
> > > misalignment and seams in the full 360x180 pano.  i tried to fix this
> > > by working with the control points, but ended up going in circles
> > > (quite literally!).  i then decided to look at only the 12 images that
> > > make up the 'level' cylindrical pano.  when adding control points, i
> > > noticed i was having the same problem, but less pronounced.  my next
> > > step was to delete all control points between the first and last
> > > images in the 12 image set.  this produced a perfectly aligned set of
> > > 12 images, however the first and last images were obviously not
> > > aligned and major errors were present between those two images.  if
> > > control points are created between these two images, the seams re-
> > > appear between previously 'perfectly' aligned images.  the seams have
> > > proven very difficult to minimize, let alone remove entirely.
> >
> > > i have carefully found the nodal point for the lens i am using and
> > > can't see any visible parallax across the images.  i am using 16-bit
> > > tiffs from ufraw, they are pretty big (about 73 megs each, 810 megs
> > > for all 12), so its might not be feasible to post them.  i can re-
> > > process them as 8-bit (about 400 megs for all 12).
> >
> > > i'm using hugin 0.8 and autopano-sift-c from svn.
> >
> > > is this normal?  am i doing something wrong or missing a step?
> >
> > > thanks for any help!
> >
>

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