Before anybody asks Yes I searched and read several filter topics already, but none of them seemed to answer all my questions, and a couple actually created more questions so here it goes: First off right now my lenses consist of Canon EF-S 18-55 (kit) and EF 50mm/1.8. To save any trouble they're filter sizes are 58mm and 52mm respectively. I have the canon hood for the 18-55 and am thinking I want to just get a cheepo 52mm screw on for the 50/1.8. Here's where the questions start: 1. If I use a screw on lens hood, do I need to make sure I get one with threads for a filter also? 2. I hear a lot of talk about UV filters for protection. Does this mean once you guys put a UV filter on you do away with the lens caps? I am very much liking the idea of not fiddling with lens caps anymore espically with the hood on one. It seems to me though that in due time the filter will still end up getting scratched. Not true? 3. Ive seen arguments for good filters being "why put a $5 piece of plastic on a $1000 lens". Well I'm in the opposite situation right now. I don't want to spend $100 dollars for a filter on a $70 lens. Does anybody have any recommendations for a more budget filter? I don't really see either of these sizes being of much use in the future either because it seems most of the lenses on my shopping list are 67mm. 4a. Polarizing filters (this is a two parter). Which do I want, circular or linear? I think its circular but will that eliminate the problem of my rotating front element or will I continually have to be adjusting the filter when outside?. 4b. Is it safe to leave a polarizing filter on when shooting indoors also or does that somehow lessen the ability of the lens to shoot in low light? This question is mainly geared for the 50mm/1.8 because if I'm using the 18-55 I will almost always have my speedlite 430ex on. 5. What filters would YOU suggest for my current setup if any (again remembering that I don't really want to spend more than the lenses cost).