The other day, while I was working on my star trail photography album and vacation pictures, I accidently updated all files’ modification time incorrectly. Whoops! For some reason, the “undo” was not a choice. And without proper chronological sequence, there was no way, my post image processing software was going to give me the exact star trail picture. After you chase weather for weeks, and work-out details like a perfect clear sky, no air planes and spend almost entire night in winter taking really long exposure pictures, this not even the last thing you want to happen. What a mess!