Here's a brand new video from earlier today. Sponsored by Adorama in NYC. Features one of Adorama's popular You Tube photographers, Daniel Norton. It is a "workshop" type video in Daniel's studio photographing a single model, head & shoulders. Of particular interest is that he is using an X1D with the 90mm lens, along with Broncolor strobes & soft boxes. Of even more interest is how incredibly sharp the images are. He is shooting tethered via Phocus, and zooms in to 100% (at least) to show the eyes on most of the shots in Phocus. He uses manual focus with focus peaking, shooting at f11. (1/250 sec to keep down any ambient light). I am just in awe at how sharp the eyes are. Enjoy.
Note - Checking eyes begins around 21 min into video.
https://www.youtube.com/watch?v=URu32284HBA