Filter Types & Uses
How Do Protection Filters Work?
While lenses do get scratched and broken their more frequent—and insidious—enemies are moisture, and abrasion from dirt, dust and incorrect/excessive cleaning. Protection filters help to protect a lens’ front element against all these mishaps (which at worst will destroy your lens and at best will degrade your image quality) for a mere fraction of the price to repair or replace that front element.
Made from clear, toughened glass, protection filters screw onto the front of your lens, shielding the lens surface without affecting the exposure or colour of your photos. Because they’re clear, they needn’t be removed from your lens unless you want to use a different kind of filter. (However, a protection filter doesn’t replace a lens cap, which will protect your lens-mounted filter when the lens isn’t in use.)