Sep 24, 2016, 08:42
I thank you for all the suggestions. I knew I came to the right place for advice!
And I finally nailed the problem! WDHewson came closest to the answer. I live in an older apartment building and buried somewhere in the plumbing is an airlock. With all the pipes banging , even though I can't hear it, and probably some of the other sources of vibration like the elevators and washing machines, t with all that the floor is vibrating quite a bit, though I have never felt it. Took pictures at 3am when everyone is in bed and they are nice and sharp. Guess I'm going to have a few late nights!
Thanks again to everyone for all the suggestions.
And I finally nailed the problem! WDHewson came closest to the answer. I live in an older apartment building and buried somewhere in the plumbing is an airlock. With all the pipes banging , even though I can't hear it, and probably some of the other sources of vibration like the elevators and washing machines, t with all that the floor is vibrating quite a bit, though I have never felt it. Took pictures at 3am when everyone is in bed and they are nice and sharp. Guess I'm going to have a few late nights!
Thanks again to everyone for all the suggestions.