B+W 55mm MRC F-PRO Digi Pro (Chrome) Digital UV/IR Block Filter 486

B+W Digital UV/IR Block Filter 486. This B+W 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.Unlike most conventional filters, the B+W 486 Filter does not block by absorption, but by interference. The unwanted UVand IR radiation is repeatedly reflected between the multiple layers, only removing the wavelengths at either end 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. The most notable application for this filter is with the Leica M8 camera, which due to its construction, can only be equipped with a minimal IR filter on the front of its sensor. This has led to magenta casts in dark subjects in certain lighting conditions.

The use of a 486 filter on th efront of the lens is the way to deal with this issue. 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 and are MRC coated.