Re: Strip assembly panoramas with a digital slr -- for stereo etc

Here are some pics of the rig I shot this pano with:
http://www.mediavr.com/stereohead2.jpg
this is the whole assembly

http://www.mediavr.com/stereohead3.jpg
this is the indexing mechanism

http://www.mediavr.com/stereohead1.jpg
this is the miniature gearhead motor that I use to drive
the gear from click to click (I control it with a remote button)
-- I listen for the 2nd click to know when to stop pressing
-- with the little drive gear I filed some teeth off to handle
the momentum of the gear head motor after the current is off
so it doesnt press the main gear


there are 240 teeth = 1.5degrees
normally I move the gear on two clicks at a time = 3 degrees

Peter Murphy
http://www.mediavr.com/blog



>
> http://www.mediavr.com/cerberusr.htm
>
> This is a (unretouched) spherical pano of a cave but not stitched
in
> the usual way ie. blended images -- it is assembled in a few
seconds
> out of 120 (3 degree) very narrow vertical images strips with no
> blending at all  -- using the mosaic tool of the excellent
> Stereophoto Maker.
>
> It is the right shot of a stereo pair. It is the middle exposure of
> bracketed sequences. I havent enfused the other exposure panos with
> it yet.
> It was shot with a very accurate 120 step indexing head I made from
a
> large gear with a strip of brass clicking into the teeth
>
> The camera here is to the right of the zero parallax point as it
> rotates by about 7 cms but still because the steps are so small
> perspective jumps are mostly invisible and the light (surprisingly
> one might think) seems constant across the joins.
>
> Each strip is a 3 by 180 degree equirectangular strip from a
5D/Nikkor
> fisheye -- generated very quickly in PTGui or via a script with the
> Panotools plugin.
>
> Why would you want to make panoramas this way --
>
> -- well you can totally automate the stitching process -- it is
more
> forgiving of slight positioning errors than standard template
> stitching (here with stereo panoramas the mispositioning is extreme
> compared with standard stitching practice  - yet still it stitches
ok
> automatically)
> -- though you must be careful with the constancy of the alignment
of
> the camera tilt and roll with the rotation axis -- I use a digital
> level to check)
>
> .. it is good for stereo panoramas using either the two cameras (or
> one camera with shift) or single camera/single rotation methods
>
> .. it is good for scene contrast as you can put a custom lens hood
on
> the lens to give a narrow strip view of the scene ... and hence is
> good for hdr panoramas too.
>
> Peter Murphy
> http://www.mediavr.com/blog
>