How does the UV filter work?

How does the UV filter work? I don't understand this!

The eye can see light in the wavelengts 300nm - 700nm approximately, UV light

is in the 250nm range. I suppose that a DSLR camera has a limited frequency

range in the range of what the eye can see. Can someone explain how and why to

use the UV filter?

 

Thank you!

 

-Jiazi

Both film and digital sensors are sensitive to UV light (digital sensors are also quite sensitive to IR). The range that the digital sensor is sensitive to is determined more by the filters over the sensor than the sensor itself, as both short (UV) and long (IR) pass filters are installed. The UV filter over the lens augments the installed filters.

I have seen it possible that you can gut your digital camera(dare you try) and remove the IR filter (Which rests just above the sensor surface) and replace it with a new filter to block visible and uv light, enabling you to make digital IR pics! kinda neat results for someone with cash to toy around with. I've never done it tho...

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<a href="http://www.lifepixel.com/digital-infrared/samples.html">http://www.lifepixel.com/digital-infrared/samples.html</a>

I really don't know about the camera filter mechanism. But i can contribute in a Physics aspect of your question. What does a filter means is that it blocks some sort of light (in your case). So in general a coating of material is given on a substrate ( glass normally used). The materials used absorbs those radiations and transmit the other radiations of non absorbant wavelength.

Ok i've read the article http://www.photo.net/equipment/filters/ on UV filters. But if u want to use a UV filter as a protective filter, then why don't u choose the B+W UV filter, since this filter transmits almost 100% in the visible reigion?