The Tiffen Series 9 Combination Color Conversion 85/ND 0.9 Glass Filter will produce natural colors when shooting with tungsten film outdoors. Without any filtration, using tungsten film in daylight will produce a bluish cast in a photograph.
Neutral density filters have several uses and offer the possibility of achieving otherwise unachievable results. Neutral density filters appear gray and reduce the amount of light reaching the film. They have no effect on color balance. Often it is necessary or desirable to balance the light intensity in one part of a scene with another. This is especially true in situations where you don't have total light control, as in bright contrast-filled landscapes. Exposing for the foreground will produce a washed-out, overexposed sky while exposing for the sky will leave the foreground dark and underexposed. This filter enables cloud detail to be kept correctly exposed in the picture.