Ultraviolet (UV) Filter
Neutral Density (ND) Filter
A polarizing filter cuts reflections from water or glass which gives a subtle look and objects do not appear very shiny. It also enhances colors and reduces haze. Polarizing filters are very useful when taking photographs indoors. You may have experienced that when you take a picture of a person wearing glasses their eyes don’t show since the reflection from their glasses obscures them, a polarizing filter will cut out the reflection and the persons’ eyes won’t be obscured any more.
These filters reduce the amount of light entering the camera which gives you the benefit of taking a longer exposure; it is good if you want to take a picture of flowing water like waterfalls, or streams, the resulting image will make the water very smooth. These filters come in 0.3, 0.6, and 0.9, which lowers the f-stop by 1, 2, and 3 respectively. Addtionally, some ND filters are adjustable and others have a gradiant effect only affecting the top or bottom half of the image.
A UV filter is usually clear and in most cases serves as a protector for the main lens glass. A nice lenes can get scratched or get dirt water or junk on it, since these lenes can get into the $1000's of dollars it is important to protect the front glass (called element). A UV filter can also help get rid of haze in the background. UV filters don’t affect the majority of visible light, so they are a perfect form of lens protection and they will not alter your exposure. There are some “strong” UV filters that are more effective at cutting atmospheric haze and reducing the notorious purple fringing that sometimes shows up in digital photography. Purple fringing is a purple ghost that you see at the edges of a subject when it is slightly out of focus.
Soft focus filters, do exactly that, they reduce the sharpness of an image, but only to an extent that is barely noticeable. They are useful in shooting close up shots of people’s faces. With the help of a little diffusion; imperfect skin conditions are replaced by silky smooth skin. Remember you can use soft focus filters while photographing landscapes or monuments as well.
Soft Focus Filter
There are specific filters for B&W photography that lighten similar colors and darken opposite colors, thereby enhancing the monochromatic look. There are Red, Orange, Yellow, Green and Blue filters for use in B&W photography.
Red filters are a favorite among landscape photographers and are often used to add drama. In nature photography, a red filter will increase the contrast between red flowers and green foliage. A red filter will deepen a blue sky and make white clouds pop out. It can also decrease the effects of haze and fog. In some cases, depending on its strength, a red filter could even turn the sky black.