UV filters are needed in order to delay the ultraviolet rays.
Such devices as the filters used in a film camera, and sunscreen lotions and creams in the form of special materials.
To understand how they work, you should first understand what the UV light, and why it should be blocked.
The visible spectrum of light the human eyecooling towers from red to violet. At the red light is the longest wave, while purple is the shortest. If the wavelength is greater than the red, it is called infrared. If it is shorter than the violet, it is called ultraviolet. The wavelength of light is measured in nanometers.
The light wave is shorter than 400 nm is called ultraviolet. If the wavelength of 700 nanometers, we are talking about infrared light.
UV filters for cameras
Why delay the ultraviolet light whenshooting? The answer lies in understanding how the film in the camera. There are three layers are sensitive to light. One of them responds to green light, the other a red and three blue. The last layer reacts not only blue light but also in the ultraviolet. If there are a lot of ultraviolet radiation, the end result gives the picture more blue color, than I would like.
Since the film is not sensitive to infraredlight, and the filter is not needed for it. Interestingly, digital sensors are sensitive to infrared radiation, in digital cameras and cost appropriate filter.
At the level of UV radiation is usually the seafew. A quantity, which arises from tan, is still present, but it is mainly dissipated in the atmosphere. If you climb higher into the mountains, and the amount of ultraviolet radiation increases. In this case, the ultraviolet filter will prevent the appearance of a blue color in the photographs.
UV filters in sunscreens
Ultraviolet rays can damage the skinhuman. It burns and long-term skin damage. How strong will the radiation depends on many factors. This proximity to the equator, and the time of day and the weather and the season, and height. Good UV protection will stay in the shadows, but even this does not always save.
The most dangerous to human health are considered to UVA and UVB rays.
For protection against ultraviolet light use special creams or lotions containing blocking filters.
Sunscreens and lotions include two types ofactive ingredients. Inorganic particles such as titanium dioxide or zinc oxide, to form a physical barrier and pushing dissipating wave ultraviolet. Organic compounds, conversely, absorb ultraviolet light and convert it into heat energy.