The Protective Filter Craze
I see this so often on the various forums and message boards. People buy a camera with a kit lens and feel the need to stick a UV filter on it.
Now, let's face it, kit lenses are good value for money but they are often not the greatest lenses on the market. Why would you run the risk of lens flaring by adding some glass to the front of the lens? Most lenses are designed as a whole package. From front to rear element they are designed to bring a good image to your sensor (or film).
What are you protecting your lens against? I've used SLR cameras for about 20 years now and I have never had front element damage. Take proper care of your gear. Use a lens hood whenever possible and use your lens caps.
Of course there are circumstances thinkable when you'd want to use a protective filter. If there's stones flying around or if you are in a situation where there's salt water spray or beer flying around for example. So, it can be useful to have a protective filter in the bag. When you do buy one, a skylight or a UV filter don't try to save money there. Get something at least multicoated. The Hong-Kong based firm hvstar has excellent prices on filters and good customer service.
Even with good filters, such as the 62mm Nikon circular polarizer, I own you still need to take care or you will end up with this:
For further reading I suggest reading what Thom Hogan has written on the subject.