Long time lurker of the photography forum here! Apologies for the "newbie" question, but can someone explain to me the basics of filters, and perhaps while you're at it, metering!?! I recently purchased a 400D (& Kit Lens) having wanted to take the plunge into "proper" photography for quite some time. I had previously read up on a lot of the theory on exposure/apertures/shutter speeds etc, but am quickly finding that real world experience is far more valuable and am enjoying playing around with various settings to achieve different results. One thing I haven't the foggiest on, is filters, and the results that can be achieved through using them. I was advised to purchase one to protect my lens, but am aware that not only are their several types, but also sizes. Which one do I need, and where do I start when it comes to looking at others?! I'd also appreciate some tips on metering - both an explanation on what it is, and what can be done with the various types of metering available on the 400D. Any advice gratefully received! I look forward to reading your replies, and to being able to play a more active part in here now i've "joined the club"! Kelvin.