After a few years using Powershot cameras I finally took the dive and bought my first DSRL: a Rebel XTi. Nice camera, I am having fun playing with it.
So I dug deep into my closet and pulled out my old camera equipment from my high school phot classes and surprisingly I still have some Hoya filters in good shape, three of which are the same size as the kit lens on the Rebel: 58mm. The filters I have are 80A, 81C and FL-DAY. I understand that most of what these filters do can be done digitally, especially with the RAW files, but is there any validity to using filters on digital cameras? I think a skylight filter would be mandatory to protect the lens and I am looking forward to buying one soon, also maybe a polarizer filter (I used one a lot back in my high school days). Besides those, what other filters are valid for digital use?