Sigma 10-20mm lens

Does anybody know what the angle of coverage would be on a sigma 10-20 used with the Nikon D2x ?

My guess is a little over 108 degrees.

I have attached an image from my 1ds/16-35mm at 16mm (108deg, 10min), and an image from my d200/sigma 10-20 at 10mm they are pretty close in angle of view, the sigma a smidge wider.... maybe....

They were both shot from the same unmoved tripod for direct comparison - the height is a couple of cm different as the 1ds is taller than the d200.

The Sigma lens specs up at 102deg 4mins on the sigma chip, which is 20.7mmx13.8mm in size.

The d200 chip is bigger, 23.6mmx 15.8mm, so captures a greater area at the same focal length, hence the greater effective angle of view. The d2x cmos chip is 23.7 x 15.7mm , so would get a smidge more horizontally, but a smidge less vertically than the d200 chip, in theory.

Just for interest sake, the 1ds showed what I would call full frame in the viewfinder, where the d200 is definitely shows less than the full frame in the viewfinder. I'm not sure what the d2x viewfinder specs are.

image/attachment number 3370 is the 1ds , 3371 is the d200

BTW Nikon specs the 12-24mm DX nikkor as 99 degrees.