While looking for some filters for an EF-S 10-22mm I've come across a number of these, "Slim filters - designed for use with wide angle lenses to prevent vignetting." Of course, there is a pretty good price difference, and some manufacturers don't have front threading on the slim models. Is this a major issue others have experienced? First the decision to buy a "digital" filter or a "regular" filter...now "slim" vs. "regular"? Why do I feel like I will be ordering my filters from Starbucks soon. I'll have an iced ND4, slim, digital-coating, soy, no whip. Any thoughts or experiences with vignetting on wides (17mm or more) when you affix a filter?