Is it any real surprise that photographs result in "UFOs" whilst none were seen at the time when photographs are a
representation of reality
that is subject to
aberrations/imperfections?
As Nohup so rightly said, do people generally pay attention to a bird flying past in the background? Why would you
not expect to find something
unidentified from time to time in a photograph since the photographic process is a. imperfect and b. a compromise between capturing a perfectly
real snapshot of reality and the limitations todays technology imposes on us.
A "perfect photograph" produced by an "ideal camera", would freeze any and all motion due to an infinitesimally small exposure time, at the same
time as gathering enough photons to accurately portray the brightness of objects ranging from those in the near pitch-black to the brightness of a
supernova from our sun, and correctly render every tone of color in a scene.
Such a camera is impossible, and could never exist due to the laws of physics. Today's most advanced cameras don't even come close, although with
proper use, amazing results that please the eye can be achieved, but there will always be imperfections and artifacts, as well as objects that are
rendered differently to how we would see them.
Buy yourself a bag of birdseed, and spend a few evenings in the park as it's starting to get dark (so your shutter speed is long) with your camera
taking as many shots as you can whilst making sure to include lots of sky, and see how many "UFOs" you catch.
In the mean time, consider this photograph. I could say virtually every light in it was "unidentified". But we all know that cars make streaks of
light as they drive down unlit roads, and sometimes streetlights in photographs have "spikes"...
The point I'm making is that a photograph is
never a 100% true representation of reality, and should never be taken as such. A camera does not
"see" in exactly the same way as a human does, so things that a human does not see may be made more apparent and distorted depending on the
circumstances and the type of imaging system used.
Ultimately, the less perfect the imaging system used, the less chance you have of identifying common every day objects in a photograph, especially
when taken under difficult lighting conditions, and when objects and/or camera are in motion. So it follows that you will get more "UFOs". Its not
rocket science.