B + W XS-Pro Digital 010 UV Haze filter MRC nano 77mm (Electronics)
I ahbe my filter for the EF 70-300 L IS USM (filter diameter 67mm B + W UV HAZE filter (67mm, MRC Nano XS-PRO digital)) bought, as these expensive lenses in my view, the protection of the front lens is indispensable. I ahbe all my lenses with (UV) fi