Spherical Panorama's

This album shows various spherical panorama's in different projections.

A spherical panorama is an image that represents a sphere around the camera. It is typically obtained by taken a series of overlapping photographs all around the camera, including the zenith and the floor (the nadir).

These images are then stitched together to represent the total sphere around the camera.

Typically, using a 17 mm objective on a full frame camera, about 20 images are needed to fill the complete sphere.  However, when large contrast exists, HDR images are being taking, typicllay resulting in 3x20 images to be stitched and blended together. This is often the case, e.g. outside, where one image may contain the sun, and another lots of shadows.

A very useful program for the blending and stitching is PtGui.

After the stitching, the sphere has to be projected onto a flat surface, in order to be shown as a picture. PtGui supports different projections for this purpose.

A very useful one is an equirectangular projection of 360 degress wide and 180 degrees high, since that contains all the pixels, from which the sphere can be reconstructed.

This image can also be viewed in this album as an interactive panorama, where one can rotate around in the sphere and obtain a good sense of the location.

The equirectangular projection can also be used as input into other tools. One such a tool is Flexify 2, by Flaming Bear, that can produce foldings of the sphere, that can be glued together into e.g. a cube or other polyhedra. It can also generate a variety of wild projections, as can be seen in this album.