2. Generating good
handheld panoramic shots

You can create a decent looking panoramic image with out a tripod. It
will not be technically perfect, since you cannot rotate the camera
precisely. But you can minimize the defects by:

Starting small. Fewer shots and smaller images are
easier. At first,
try a single row instead of double row panorama. If you want to capture
the entire scene, capture 2 x 180 degree panoramas, as a 360 is much
harder to stitch, since there is less room for fudging the errors.

Excluding close up objects. The closer an object is to
the camera, the
more it will be affected by parallax, a distortion of the relative
placement of an object in space. Parallax helps us see in 3d,
but it
will cause ghosting in your panorama.

Setting focus and exposure manually. 
Preplan the shot, by
scanning, watching the exposure, and selecting settings that are in the
middle of the range.  If you can’t manually set your
exposure, setting it on that middle scene is a good alternative. Focus
works the same way, but is not a problem if you are shooting a distant
vista.  If you can lock it do so.

Overlapping by at least 30%. Overlapping the individual
shots by a generous
amount gives the software more data to use in stitching. It also
minimizes the chance that you will create a gap. For these shots,
don’t worry about keeping a precise overlap. The software
will figure it out. You will want to avoid moving objects in the
overlap if at all possible. They can cause ghostly headaches.

Keeping the camera at the same level. Look
at the horizon, and
keep it at the same spot in the frame. Practice is the key to keeping
your camera level as you rotate.

Taking shots outside of your intended final crop. The
handheld variations
will require cropping – plan ahead for it. Use a wider lens,
rotate the camera into portrait orientation, or zoom out to give
yourself more leeway.

Taking duplicates. You can choose the best
ones –
people move, clouds and lighting change. I like to take one complete
set, then repeat at a little different orientation. Another strategy is
to take a horizontal or vertical “patch shot” as I
go.

Trying to rotate around the camera, rather rotating the camera around
you.
One method is to hold the camera over your foot, and rotate on your big
toe. Another handheld method involves holding the camera against the
bottom of your chin and sighting through the middle of the lens to a
spot in the ground. The person then rotates keeping the camera aligned
with the spot, and the head level. You need to be able to visualize the
area covered by your lens so you can rotate effectively.
Don’t get too caught up on the nodal point issue. It really
doesn’t matter if the objects in the picture are far away.
Getting the camera level will have more of an effect because of the
need for a final crop.

3. Handheld Panorama
Results

For an experiment I took the same panorama three ways: first with the
camera at arms length, rotating on my heels, then as close as possible
rotating around the camera, then rotating around the camera, but
deviating the angle by 10 degrees or so as I panned.

Using Autostitch , one of several free stitching
programs; gives pretty
good automated results. Be sure to rotate the images before hand, or by
setting the appropriate options setting. We have an 
Autostitch tutorial {link}here. If you want to get a bit more serious,
Autopano Pro {link} is a recommended stitching software with the
Autostitch
technology (and a lot more) built in.

I tried to simulate a basic “point and shoot”
situation, walking up to a view and shooting away with my Canon
S70.  The camera
was held in portrait orientation to maximize the vertical coverage. The
metering  and focus varied across the shot between 1000 and
2000th of a second.  I tried to shoot quickly to minimize
issues from changing light as the clouds blew past the sun.. The point
was to push the boundaries, and show which variables are most
important.
A quick look at the pictures shows that all three are in need of a
crop, but that the tilted shots are the worst. This is the #1 thing to
keep in mind when shooting panoramas. #2 would probably be
lighting/exposure, but even that isn’t horrible. Panoramas
are more susceptible to high contrast issues since the pan drastically
changes the location of the sun.

Results: 
My technique in this test was not my best. Both of the rotate camera
and rotate
person methods drifted from horizontal significantly. (2802 
pixels high or 7.5% error for person rotation, 2704  or 4.2%
pixels error for camera rotation height with 2592 pixels
being ideal.) However, neither was as bad as the intentional
tilting. 
It has drop outs where I lost some of the foreground. The reason that
the gap is small is that the overlap saved me. Other pictures contained
most of the missing shrubbery. Here they are:

Image One, rotating the camera around me is the best of the three,
though it will require cropping. The section with the stitching error
is highlighted.

Image Two, rotating myself around the camera, has more drift. The red
tint shows the required crop.

Image Three, intentionally tilting the camera as I rotated, is clearly
the worst.

In rotating the camera, I was able to keep a steadiest hand, but what
about parallax? In scanning around each image, I found an
instance
where a fence was misaligned. (See Image One for an indication of the
area.) In all honesty, it could be an issue with
rendering of diagonal lines, but it was detectable at 300%
magnification. None of the other areas of overlap showed any
problems.
I restitched the images in Autopano Pro, and didn’t have the
problem. (It has smartblend, which covers for such errors.) Still, it
is not a big deal. In order for the error to begin to matter, you would
need to print the image at 24 inches x 9 inches. Even then, you would
need to stand 5 inches or so away to see it. My conclusion: for vista
type pictures of far away objects, don’t worry too much. But
try to keep the camera as level as possible.