Sigma AF 120-400mm F4.5-5.6 DG APO OS HSM Specifications
Diagonal Angle of View:
20.4° - 6.2°
Number of Aperture Blades:
Hyper Sonic Motor, rear focus
LH 830-01 (bayonet mounted, round shape)
The lens came with detachable tripod collar TS-31.
Sigma's OS seems to face similar incompatibility problems with old analog bodies like Canon's own IS lenses. I.e. Sigmaphoto.com puts a note to many fullframe OS lenses either reading "This lens cannot be used with film SLR cameras with the exception of the Nikon F6 and Canon EOS-1v." or (seemingly making the issue more clear) "For Nikon and Canon mounts, Optical Stabilizer (OS) function will not work with film SLR cameras except Nikon F6 and Canon EOS-1V."
Sigma reported slow down problems with the EOS 40D for lenses with SN below 1011001, when the camera was set to servo mode with the lens' OS activated. A service update was/is available.
Sigma reported Live View issues with the EOS 750D and 760D for lenses with SN #12971601 or later: When the Live View Mode button on the camera body is pressed, operation stops. A service update was/is available [source