The B+W Series 7 FL-D #499 Glass Filter can be used to get clear pictures while shooting daylight film under general purpose fluorescent lighting.The blue and blue-green portion of the visible spectrum is blocked up to 520nm by this glass filterThe excessive sensitivity of color infrared films for this spectral range is reduced by the B+W series fluorescent glass filterWith the help of this daylight circular filter, you can avoid blue tint and differentiate colors more evenlyThe B+W Series 7 FL-D #499 Glass Filter is useful in indoor photography where a lot of green would appear because of the fluorescent lighting