* Prices may differ from that shown
'Filters' are circular pieces of glass which fit onto the lens of an SLR camera. A filter can serve many purposes, and I personally use them for two reasons.
Firstly, and perhaps most importantly, they protect whatever they are fitted onto. If you're using a £1000 lens (not that i've got one of those), then you don't want to risk scratching the glass at the front and ruining the product.
Secondly, I specifically use a 'UV' filter (like the Hoya Pro1 Digital which I am reviewing here), to absorb the ultraviolet rays which often make outdoor photos look hazy.
This particular filter costs £28 from Amazon, but I order them from Hong Kong for around ten pounds less. There are cheaper UV filters available, but many of the lesser priced ones are not 'multicoated'. The coating on a filter is extremely important, and reduces lens-flare and reflections on the glass. If you were to hold up a cheap uncoated filter next to the Hoya Pro1 Digital, then you can do a test which will clearly demonstrate which is the best.
When looking through the cheaper filter, you can usually see a milky looking view of the world, which is down to; a) The deficiencies in the inferior glass, and b) The reflection of light on the product. When looking through the Hoya filter, it is as if there is no glass there at all.
The Hoya Pro1 Digital Filter has a screw fitting and comes in a small plastic case with foam padding inside. It really is an excellent product, and out of all the filters I have used over the years, I have found this one to be the best.
Hoya PRO1 Digital absorbs the ultraviolet rays, which often make outdoor photographs hazy and indistinct. It is a multi-purpose, fine-weather filter for color as well as black and white films. Also serves as a permanent lens protector.