Thanks for taking the time to shoot the stuff that you did. This can also give me an idea if its really worth spending the extra money on a MC filter since I don't own both types of filters. Where I see most of my problems is when the camera will be on a tripod at about chest level looking into a room or a scene pretty much directly in front of a window with 3 to 6 lamps scattered around inside. The bed is usually in front of the window with a nice bedspread, comforter and a decorative end blanket which is most often brightly colored. The round flare happens right on the decorative end blanket on the inside of the bed where the shadow falls. Its a very high contrast scene where my L lens even struggles to get a constant level of contrast and color plus the general area can get washed out as well. Another time that I see the flaring is when there are bright lights, floods, directional lights in the ceilings and there is no way to avoid getting these lights at the angles where they don't enter the lens even with the hood on. Also the main light source is usually a large window maybe five feet tall by anywhere from 4 feet to 6 feet wide and it will be the only window so its usually bright light entering an otherwise dark room.