Here are a couple images taken recently with the Z9, the 400mm f/4.5, and the 1.4x TC. The first image was taken on Jameson Lake, in Moses Coulee, eastern Washington, while the second image was taken in Steamboat Rock state park, in Grand Coulee, eastern Washington. The young deer in that second image was eating a fallen yellow leaf, which was a surprise to me (vs. eating just grass).
