I always like to test the limits of my camera gear and this morning was no different except that I actually looked at the exif data and was surprised at the distance I was sitting away from this eagle perched in it's nest tree.
The first image was at 1200mm using a Canon 600mm f/4L II with a 2XIII extender. The second image I added an older Kenko 1.5 non-reporting extender giving me a total of 1800mm focal length. I lost 2 stops of light but I was still able to autofocus and I was using my truck mirror to support the camera/lens.
These eagles are very skittish so I stay in my truck when I visit the nesting area. Not many people know about it's location and the ones that do don't bother visiting it because it's off the beaten path and it's a hard to reach nest with camera gear. There is also a limited view of the nest because of the trees surrounding the nest tree so there's not many opportunities for in-flights plus it's hard to swing a 600mm lens sitting inside a truck...lol.