Vincent,
The 5D the 10-17 with the lens shade cut off basically gives you an uncropped fisheye view from about 14mm upwards. Below this you get a circular crop effect. Of course, this is what you need to make a spherical panorama. If I set the focal length to around 11 or 12mm the circumfrance of the crop circle just about touches the edge of the frame in the long dimension. Holding the camera in the portrait orientation and rotating it around the nodal point (or no parallax point) of the lens- using a tripod and a specially made panoramic head to fix my Ikelite housing to the tripod, I can get a full 360 view in four shots. I then use stitching software to produce either a Quicktime VR panorama, or a flat panoramic 360 image which I can then reproject to a stereographic projection.
Anyway, it might be simpler to show some images. Havn't had the chance to try it in a great diving location yet, but here are a couple of my experiments:
First- this is the field of view at around 11 or 12mm with the 5D and lens shade removed:
and this is a stereographic reprojection of a spherical panorama made by stitching four images similar to the above together.
It's fairly early days yet with experimenting with this setup. I havn't got an easy way to post one of the Quicktime panoramas at the moment. Am hoping to try a few more next month in the Red Sea.
I might try it soon with the sigma 8mm, which projects a circular image on the 5D, this way I could get my full 360 image in 3 (or even 2) shots, which might be handy if there's lots of movement in the frame.
