What affects the quality of the cameras photo or video

There are various factors that can affect the quality of a photo of a persons face.  

1. The height the camera was installed would affect the quality of the subjects photo. The quality of the photo degrades when the camera is further away from the subject. 
2. If the photo was taken at night (IR) 
3. The distance the subject was from the camera when the photo was taken. The closer the subject is to the camera, the better quality of the photo or video.
4. Lighting conditions: if the light is to low or light is to bright. If there are shadows on the subjects face.
5. If a subject is moving, a motion blur can attribute to an unclear photo.
6. If the lens dirty.
7. Weather conditions