By far the most important accessory you can
buy for your professional camera lens is a
high quality filter. B+W filters are valued by
professional photographers for their exquisite
optical quality and fine multicoatings. B+W
is a must have for every pro quality lens.
This dark red filer is for black and white infrared films and filters at light below approximately 650nm. It allows pictures of a pure red image while making good use of the relatively low sensitivity of infrared films. Filter factor is approx. 20-40.