They do not affect a colour balance on a picture and bring longer exposure times to obtain interesting shots of moving subjects on photographed scenes.

The filters are most commonly used to:

• Prolong shutter speed to capture such subjects as: waterfalls, brooks, moving vehicles.
• Obtain larger aperture opening with the same exposure time to highlight a person or a subject and get a blurred background effect.
• Shoot in intensive daylight with ISO sensitivity above 400.
• Ensure stable shutter speed to record scenes with a very bright background, such as snow or sand, which could cause overexposure of photographed or recorded scene.