Diagnosis
Fingerprints or dust on the small, recessed camera lens are a common culprit for blurry or foggy video. The lens is delicate.
How to Fix It
First, use a dry, soft microfiber cloth—like the kind for cleaning glasses. Gently wipe the lens in a circular motion. If moisture is needed, breathe lightly on the lens to fog it, then wipe with the dry microfiber. Do not press hard.
If That Didn't Work
If the smudge is stubborn, dampen a corner of the microfiber cloth with a tiny amount of distilled water or lens cleaner, wipe gently, then immediately dry with the other side of the cloth.
Heads Up
Never use window cleaners, alcohol, or abrasive cloths (paper towels, t-shirts) directly on the lens. They can permanently damage the special coating. Also, check the inside of the clear plastic camera housing for condensation, which would require taking the unit apart—not recommended.