There are cheap zoom lenses which use 72mm winding (or what is the correct english technical term?), is there an adapter 72 to 82mm to use these tele lenses?
I have over ten different step-up and step-down rings, and I still find myself needing new ones all the time....it's worth it to find a high quality, cheap source of the rings and just start buying a bunch....they can often come in handy.
I will say this though: Using lens adapters with step-down rings doesn't always work out well, as you often end up using much more of the glass then was intended and end up with distortions and such.....or you may find yourself having to zoom heavily in to eliminate distortions, although this is more of a problem when you're trying to go wider.