This is a non-wildlife question/problem but I wanted to see if anyone here will have some insight. I setup a timelapse earlier this month to catch a transition from sunset/night/sunrise and found that the focus was changing during the timelapse even though I had set it up in manual focus (although somewhat off). The picture gets blurrier when dark and is better when it is lighter. In NXStudio, the focus mode is manual with single-point AF, but the VR was turned on in Sport mode. Can this be causing the changes, the VR attempting work while on a tripod? I have had a similar problems years ago doing some astrophotography; turning off VR fixed the problem.