Two reasons to have this Tiffen filter on your lens:
1. To protect the lens surface from scratches, abrasion, etc.
2. To improve the color and tonal rendition of color photographs. In
this respect, it acts like a UV filter but is more effective with
light reflected from dust particles in the air. Here's what one
(non-Tiffen) web site says about the Tiffen Haze filter:
Haze filters are designed to reduce haze and are yellowish to counter
the excessive blue. For example, Tiffen Haze 1 reduces excess blue and
transmits 29% at 400mm wavelength, while Tiffen Haze 2A provides
greater ultra-violet correction than Haze 1 and transmits 0% at 400mm
wavelength. However, for color photography, polarizers are frequently
used. Note that although polarizers many not cut through haze as
effectively as Haze filters do, polarizer can increase the contrast of
the scene by eliminating reflection!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7624991632
