The lens used on these was a twenty seven year old nikkor 400/3.5 AI-S. She's old, slightly beat up and lacks autofocus but I've yet to find a sharper prime wide open.
First is great, you must have an amazing ability to hold the camera still, the images are amazingly sharp. I was only seldom able to produce such a sharp image with so low exposure times with my 300mm even when using a monopod. Great work!