B+W 77mm MRC UV/IR (486M) Filter

This B+W 77mm MRC UV/IR (486M) Interference Filter has a completely colourless glass carrier coated with a number of extremely thin, partially reflecting layers with precisely computed thicknesses, similar to MC coating. The B+W Filter 486 does not block by means of absorption, but by interference of the unwanted UV and IR radiation that is repeatedly reflected between these layers, affecting the wavelengths on both sides of the visible spectrum with a steep cut-off. It is used mainly on digital and video cameras with CCD sensors without an integrated IR protection filter, because the IR sensitivity of the CCD sensor would otherwise cause colour changes and unsharpness. That unsharpness results from the chromatic aberration of the lenses that are only corrected for visible light. In the visible range, the transmission curve is very high and straight. This filter is completely clear and it requires no increase in exposure. Its filter factor is 1.

77mm MRC UV/IR (486M) Filter further details

MRC
MRC (Multi-Resistant Coating) by B+W is not only an extraordinarily effective multiple layer coating, it is also harder than glass, so that it protects filters from scratches (for instance when cleaning the filters), and it is also water and dirt repellent, thus facilitating filter maintenance.