Whats the deal with Filters?

[Pricey]

Are they to protect the lens from light and things? Im just really new to filters and have been wondering if they would be any use to me on holiday.

Thanks!

[rhys]

Filters are there to change what you see. Polariser reduces relfections. UV reduces haze. Neutral Density allows for longer exposures.

[SimonG]

In some regards, they are a remnant of film photography, as colour filters were often used to correct for lighting not balanced for the film stock's rated color temperature (i.e. you are using film formulated for daylight use under tungsten lights, for example), or to manipulate contrast when shooting in black and white. To a large degree these colour filters are no longer really necessary, as these effects can be achieved either in camera, or in post. Even something like a UV filter is more or less meaningless, since today's sensors have UV blocking filters built right in.

However, there are still some useful filters. A split ND filter can be very helpful in landscapes for properly exposing both the sky and ground. A circle-polarizer filter can be used to darken skies and increase the visibility of clouds, as well as to remove non-metallic reflections from objects. Finally, IR filtes can also be used to produce an interesting effect (though this typically includes very long exposure times, unless you've had your camera's IR filter removed).

[CoolToolGuy]

You will find the topic of protection filters to be a bit like religion here - some believe in them passionately, and some say stay away. I put a UV in front of every lens I own, if the lens has a filter ring. I also make sure I have a polarizer that will fit every lens. The best advice I can give - if you buy filters, don't skimp on them. Get a filter in the quality range of the lens you are putting it on - don't put a cheap filter on an L lens.

Have Fun,

[rhys]

With protective filters there are two points of view:
1. Use them. This is generally a view supported by those that would find replacing a damaged front element/lens to be expensive and a hassle.
2. Don't use them. This is generally a view supported by those that can afford to replace worn-out kit fairly regularly. An example would be a news photographer who's more concerned with the picture than the kit as the kit represents something that can be set against tax.

Mostly (though not always) amateurs use filters and pros don't. This has nothing to do with the quality of the filtration.