I guess it is whatever works for you, isn't it. If a paving block works, then a paving block it shall be. At a star party a couple of years ago, there were several scopes set up on a wide concrete sidewalk surrounded by a huge area of grass. We were all rather surprised by the sudden appearance of jumping images in the eyepiece, only to discover that three young girls were running across the grass some 10 yards away. Who would have thought something like that would have transferred right to the e.p.? But it did. Fortunately no one was imaging. Rusty, I think spoonsize did use vertical bar with his blocks, at least that's the impression I got. Keith