why is it that UFO's are always captured on film at great distances? im sure if UFO's were flying over us at night (creating a light) or during the day, wouldnt the people that were under them take photos/video? (giving better detail of what they look like)

I do believe in UFO's, although personally ive never seen one. I believe that if we are being visited by aliens and they have advanced technology, wouldnt they also be able to cloak themselves?