Red-eye
Blemishes or acne
Scars or scratches
Wrinkles or fine lines
Shadows or uneven lighting
Noise or graininess
Glare or lens flares
Unwanted objects or background clutter
Overexposure or underexposure
Color casts or incorrect white balance
Blurriness or out-of-focus areas
Distortion or perspective issues
Motion blur or camera shake
Jagged edges or pixelation
Color fringing or chromatic aberration.