Does anyone happen to have the NPP value's for the t2i (550D) with the 8mm sigma fisheye?

Also, do I need to use a t-adapter with this camera... it seems like the camera tripod mount may be offset from the centre of the barrel of the lens. Please correct me if i'm wrong but i'm just starting out and wondering if that's the issue.

Im using nodal ninja 4 with rd16.

Thanks in advance!'