The package I use for my work is Realviz Stitcher, and a good review is
here:
http://www.outbackphoto.com/workflow/wf_71/essay.html
By the way, the guy who wrote the review (Jim Collum) is one of the people I
shoot with. He's one of the most talented landscape photographers I've ever
met, and his work is superb. You can do a search on the web to see some of
his portfolios, and it will give you a sense of the type of work we will be
using the Zuiko 24mm shift lens for.
Realviz Stitcher is a bit pricey, but you can get a discount code on the
Digital Outback site (see the discussion forums), and then the price is
pretty reasonable.
Mike
-----Original Message-----
From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On Behalf
Of John A. Lind
Sent: Saturday, April 16, 2005 6:06 PM
To: olympus@xxxxxxxxxx
Subject: [OM] Re: Lanscape's via PC stitching,
At 05:13 PM 4/16/2005, Tom Scales wrote:
>All excellent points and for some of these locations, I will likely redo
the
>shot on a tripod. Many are on a bike trail and we ride our tandem in and
>carrying more than just a camera can be a challenge (any bicyclists with
>recommendations on a good way to carry a heavy camera and have it ready to
>shoot?).
I realize there are times when it's simply not possible to do a thorough
setup, and that's the additional benefit of software such as PhotoVista
(and the "free" AutoStitch posted here). PhotoVista can do a decent job of
compensating and adjusting things in adjacent photographs that don't fit
together well . . . within some limits though.
The primary thing gained by aligning rear lens node over the tripod's
rotational axis is eliminating parallax shifts in the overlapping regions
of the images. Indeed, the "field" method of alignment creates conditions
that produce dramatic parallax shift and adjustment is made until it's no
longer detectable. The method I use is placement of a thin vertical object
very close to the camera with a very distant background that also has
strong vertical lines, or at least something against which the close object
can be seen to shift easily. The camera is then set with the near object
in view at the left edge of frame and rotated until it's at the right edge
of frame. Fore/aft adjustment of the camera is made until the background
no longer appears to shift behind the very close object. (Left/right
adjustment is fairly simple with most cameras . . . to center the lens axis
over rotational axis.)
When PhotoVista (or other stitching software) encounters parallax shift in
an overlapping region, it attempts to use the parallax of one or the other
and will "blend" things between the two in mismatching regions to hide
it. PhotoVista does this rather well, but can have problems with hiding or
blending it completely if the parallax shift is between very prominent or
very high contrast objects. The same problem occurs if people or things
move around in successive photographs in areas that overlap with adjacent
photographs. Sometimes it can hide this fairly well; other times it's
still detectable in the output photograph.
The other software posted, AutoStitch, looks as if it is specifically
geared to assembling mosaics . . . and based on what I saw in the examples,
it appears its authors made presumptions that overlapping regions might
have some hideous mismatches. I've downloaded it and will eventually play
with it using some of my less than well executed sets of pano photos. I've
managed to "kick the tripod" or do something else a few times without
realizing it and ended up with a shift in rotational axis in the middle of
the shots.
BTW, the lens you used doesn't appear to have too much Cos^4 falloff . . .
a problem I encountered the first trek out . . . using a 28/3.5 SC (which
is noted for its falloff). The same lens also produced some hideous
aperture flare! I learned from that experience that shading the lens front
from the sun is crucial, unless the sun is actually in the field of view.
Keep shooting 'em and have fun with it. When you get a good one, it looks
"way cool."
-- John
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