Big Ben's Panorama Tutorials

Photographing in Tight Spaces

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 hood

Your 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

Outside 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

Control pointsStraightening 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 found here.

Adding extra width, it is also possible to do some horizontal perspective correction by altering the yaw angle of the rectilinear image.


Rectilinear "Straightened"
Rectilinear
"Straightened"
Cylindrical
"Straightened"
Equirectangular
sample1 sample2 sample3
p w1500 h3000 f0 v120
 n"TIFF"
no change f1 f2 w1500 h2250
o f3 y0 r0 p0 v117 
a-0.02 b0.02 c-0.02
r-0.283545 p-16.0827 r-0.283545 p-16.0827 r-0.283545 p-16.0827
Cropped sample Cropped sample Cropped sample Cropped sample

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


From here...
Raw Image
to get this...
Finished result
and eventually this!

 

 





This page, its contents and style, are the responsibility of the author and do not represent the views, policies or opinions of The University of Melbourne. All photographs Ben Kreunen 2000

Ben Kreunen <bernardk@unimelb.edu.au>
Department of Pathology
Last modified: February 24, 2003