I had some flare problems with the 28mm f1.4 AF-D, so I bought the lens hood that's designed for it: HK-7. It's a slip-on hood with a little tightening screw, and it costs a bundle. Of course the lens has a 72mm filter thread. Not a big deal, right? Just use a 72-77mm step-up ring, you might say. But the step up ring doesn't fit under the lens hood even though it's a slip-on hood. Has anyone else encountered this problem? Is there another lens hood that can be used? 72mm filters are quite expensive, so I'm not about to go out and duplicate all of my 77mm filters. Happy holidays!