The Canon EF600 f4L IS

This lens replaced my 800mm f5.6 IF-ED Nikkor in 2001. While it does not have quite the reach of the big Nikon, I found the allure of image stabilization irresistable. It also has auto focus, of course, which the Nikon, being an old design, did not. This lens, aside from being twice the focal length, is operationally identical in all other respects to the Canon EF300 f2.8L IS