What are UV filters?
UV filters, as the name suggests are supposed to block Ultra Violet light. But to understand the importance of these filters we might need to delve deeper on how UV light affects your photographs and why is it necessary to block it. The regular visible spectrum of light normally goes from red to violet. Red light has the longest wavelength while violet the shortest. Therefore light which has a longer wavelength than red is called infrared, and light which has a shorter wavelength than violet is called ultra violet or UV. For film photography the blue layer on the film reacts to UV light. So if there is a lot of UV light, the blue sensitive layer gets extra exposure and the final image takes on a blue colour. Uses of UV filters: So do we need UV filters everywhere? Probably not, since there isn’t usually a huge amount of UV around especially at sea level. The UV light, however, goes up as you gain altitude. For instance going up a mountain will definitely add to the amount of UV light.
