I know that most people use filters on their lenses to protect the front-most element of the lens from physical damage. Other than physical protection it seems such filters don't do much else. My questions are: Don't filters increase the risk of flaring and ghosting and is that significant for the protection they afford? They may degrade the image if lesser glass is employed, right? Modern lenses' coatings MUST absorb UV and "skylight," right? So if one will use a filter, why not a clear glass filter? And, finally, wouldn't the public be better served if lenses, both high and low end, were sold with a filter, that could be used if desired?