K&F Concept 40.5MM Classic Series, Blue-Coated, HMC UV Filter, Japan Optics

C Series — UV filter 40.5 mm, protects the front element and filters ultraviolet light.

• Screws onto a lens with a 40.5 mm thread.

An MCUV filter does two jobs at once. It filters out the ultraviolet light that puts a bluish veil over distant and mountain shots, and above all it shields the front element — instead of a scratched lens you replace a filter costing a fraction. It has no other effect on the picture, so it can stay on permanently.

The multilayer coating raises transmittance and lowers reflectance, so the filter takes no light away and produces no veiling against the light. It also stops the glass from fogging when you move from cold into warmth.