Chuck, I do own one but found them more useful for photography than for visual observing due to edge-of-TFOV distortion. The full benefit of the TFOV increase reduction cannot be obtained visually due to field stopping. The best use I have found for it is with a small chip CCD to compress two widely separate galaxies onto the smaller chip TFOV. For this use, the technologically with more expensive wide CCD chips is the current state-of-practice. I have also found it useful with smaller 60mm refractors (either used a finder scope or separately) for the limited purposes of 1) looking at comets with larger tails, 2) displaying the full face of the Moon at star parties or 3) displaying large clusters in one TFOV (e.g. Coma B or M8). I do not own bino viewers can have not tried a nose piece focal reducer with a bino viewer. My recollection is that these are positive lenses placed more than 1 f/l in focus and therefore require a lot of infocus travel to get them to work. I'll have to check my optics notes. - Kurt http://www.scopestuff.com/ss_fr1a.htm http://www.owlastronomy.com/barlows.htm http://telescopes.net/doc/2500/mftr/Orion/item/52066 http://telescopes.net/doc/2500/mftr/Farpoint/item/FP496