These inexpensive Dorr UV slim filters, absorb ultraviolet rays which often make outdoor photographs hazy. UV rays are a particular problem on landscape photos and photographs taken in the mountains or at the coast. The amount of UV's bouncing around in these particular spots, always interfere with the crisp sharpness of the final photograph and no matter what you do to try and get round this problem, the only real solution is to use a filter at the time of taking the photo.
The Dorr UV Digiline range of filters have a slim profile to help stop vignetting when using them on wide angle lenses and they are finished in a matt paint, so that light doesn’t accidentally reflect off them, causing additional problems. It can be left on the lens as a standard multi-purpose fine-weather filter for colour, black and white films and also Digital photography as well as serving as a permanent lens protector. It’s also possible to screw other filters on top of the UV filter as long as the lens isn’t very wide angle. Made from high quality photography glass, it will not detract from the optical quality of the lens.