Big Ben's Panorama TutorialsPhotographing in Tight Spaces |
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Fisheye lenses are not just useful
for panoramic photography. Their incredible depth of field and extreme field
of view make them useful for photographing in places where space is
extremely limited. For our examples I shall use some shots I took in a
scientific lab using 17mm and 8mm lenses. The aim of these shots was to
illustrate lab facilities and procedures for handling infectious material.
The fume hoodYour typical shot of a scientist working at a fume hood doesn't really show you what they are doing. Most of the subject is taken up by the scientist and the fume hood while all of the interesting stuff is happening inside the fume hood. One solution... put the camera inside the fume hood. Outside
Straightening
Adding extra width, it is also possible to do some horizontal perspective correction by altering the yaw angle of the rectilinear image.
Which projection is the right one for the shot may well vary. The finished collection of shots used rectilinear, cylindrical and equirectangular projections. The reasons for choosing different projections usually related to either excessive wide angle distortion of recognisable objects near the corners of the image, or excessive distortion of features of the person in the shot (e.g. "fat" arms in foreground, "small" head in centre of image) Inside
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In this case, space was very limited with the fume hood located in the
corner of a very narrow lab. A 17mm lens gets everything in but there's the
fisheye distortion. So what can we do with this image? Well to
start with we can straighten it, adjust the perspective, and remap it to a
different projection. 
Straightening
was achieved using four pairs of control points (3 illustrated) at the ends
of vertical lines and then optimising yaw and pitch for the image.
Extra height is added to the 'panorama' specification to allow for movement
of the image with the change of pitch. PTOptimizer was then used to
calculate the roll and pitch of the image. The resulting script can be
