When even cellular phone pictures can take clear pictures, why are pictures of UFOs still blurry?

Answer 1

Alien light disrupting devices. The aliens realize that tiny intellects like ours can not handle interstellar knowledge. Since cameras are in essence, a photon(light)sensitive piece of film or plate that converts the light to digital information, aliens disrupt the photons around their space craft.

Answer 2

Evidently you have not seen some up close crystal clear pictures of the craft have you?

These beings are not flesh and blood like we are as they can disappear and reappear at will. They can travel through walls and take people out of their homes or cars like spirit beings.