UVfilters

A UVfilter is an optical filter designed to be mounted in front of a camera lens to block ultraviolet light. By doing so, it can reduce atmospheric haze and preserve contrast in some lighting conditions, and it also provides a physical barrier to the lens surface for protection against dust, moisture, and scratches.

In the era of film photography, UVfilters were commonly used to minimize haze caused by UV radiation. With digital sensors, which are far less sensitive to UV, the practical optical effect of UVfilters is often minimal. Nevertheless, some photographers still use them for haze reduction in high-altitude or marine environments, or simply as a precautionary front element protector.

Most contemporary UVfilters are multi-coated to reduce internal reflections, flare, and color shifts. They come in a range of sizes to fit different lenses, and many are offered in slim profiles to avoid vignetting on wide-angle lenses. The quality of glass and coatings can influence image sharpness and transmission, so high-quality, properly mounted filters are preferred for critical work.

The decision to use a UVfilter for protection versus removing it for maximum image fidelity is debated. A cheap, poorly coated or thick filter can introduce reflections, color casts, or softness, particularly in open, high-contrast scenes. Many photographers opt for clear protective filters specifically marketed as such or rely on lens hoods and careful handling instead.

In practice, UVfilters are one of several filters available for lens protection and atmospheric control, with usage depending on the photographer’s equipment, shooting conditions, and tolerance for potential minor image-quality trade-offs.