20121123-001-3 by longzoom, on Flickr. Direct morning sun inside the frame. Any flare, imperfections, unsharpness, coused by the filter? And I mean BY THE FILTER, not the usual things by low sun, very usual for any lens. D800, 28-300 at 28mm, BW filter. Any flare or imperfections on any of my already posted, hundreds of them, images taken with 28-300 lens with filter (never ever without) set? Just one small drop of rusted water from the roof, bad rain, sandy wind, you name it - and your lens is finished. Arguments about strong front elements are naive, sorry. Dimitri.