I purchased an adapter lens and T-mount from BH Photo ( http://www.bhphotovideo.com). The adapter seemed rather expensive but I discovered that it has a roof prism image erector inside as well as retrofocus lens to cover the entire image sensor of the camera. As you can see it works quite well. The whole combination is rather awkward.
For the first two eagle photos I used ISO 200, but for the newest of the eagle photos I went with ISO 100 and waited for snow on the ground to augment the light. These are captive eagles and a distance of about 30 feet.