i bought this lens off ebay, really good price, last 30 seconds, to fix a broken lens.( under 30 bucks)
well... i have no idea what type a mount this is but it isn't canon.
it is a sigma 28-300 hyperzoom, but the mount has 5 small little pins sticking straight up towards the outside of the lens. 1 by it's self, then the first of 4 is under the red dot,
it has an aputure ring, and a lever that reports to the camera the setting of the aputure ring, not electrical, the web site said something about nikon mounts not having a motor.
it is a standard bayonet mount.