B+W 72mm BASIC 486M UV/IR Cut Knurled Filter, prevents color casts and blurring for digital cameras where the IR barrier in front of the image sensor still has some residual transmittance. The 486M filter achieves this by interference, using a number of wafer-thin partially reflecting layers with a precisely calculated thickness. The 486M is clear and colorless, does not require any increase in exposure, and can also be left on the lens permanently as a protection filter.