The characteristics of film change lenses are as follows: The price is usually higher because the film needs to be applied to the surface of the lens. Discoloration speed: Very fast, discoloration is rapid and uniform, fading is also faster, discoloration can be changed in seconds, and it returns to a transparent state quickly after discoloration. Durability: low, fragile and easy to scratch, relatively short service life, need to be used more carefully. Discoloration uniformity: not limited by material, the discoloration is more uniform, and it is not affected by the thickness of the lens.