I've been shooting the last few days with a 15" APO Wolly that I picked up, still connected to the prism used in a copy camera, for $25. It's really quite sharp and contrasty. The aperture is really round - lots of blades. It seems to be a keeper for 5x7 and 8x10. I'm using a Packard shutter for now since it's in a barrel mount. I seem to recall that thos wasn't one of the "easy to find a shutter" situations, though I admit I haven't done any research yet. Wonder if I can make a focusing viewer from that prism... Hmmmm.