What are you trying to achieve or adjust for?
I personally use only the filters Elliott mentioned when I want the corresponding effect. The rest of the time I don't use one, except occasionally when there's a high risk of water splashing or significant dust blowing on the front element. Instead I keep the hood mounted to protect from bumps.
Since a filter slightly degrades IQ, and I've had a filter break and scratch up my front element before, using a filter looks like a lose-lose proposition to me.
I believe I heard someone state that you could effectively turn the IIs into an IR camera simply by adding a filter, but I don't know how accurate this is. Other than that I don't know of any ways the IIs is different from other cameras regarding the use of filters.
Last edited by DSims; 01-17-2013 at 12:16 AM.