Hi Dave: I think you've over analyzed this intially, but did come around in the end, bear with me... For true sterero pairs, the shots must be from slightly different vantage points, but not ridiculously so, for the scale of the object. The only other criteria is that the 'handedness' remain the same. If you reverse the left and right shots, depressions can appear raised, and vice-versa. I remember this effect when I was working with aerial shots for a surveying company in my lab days. Same effect with astro shots. Reverse left-for-right, and you get stars in front of the comet, not behind it. I shot many pairs of Hale-Bopp and found this true 100% of the time. And I get the same effect with the crossed-eye method as a viewer (I own an old B&L); remember all the viewer is doing is helping you do essentially the same thing. Am I mentally reversing left for right? Can't say. I only gave it a few minutes, but couldn't see a thing in the stereogram you directed me to, using either the relaxed method or crossed eye method. I'll try again as time permits. I think true stereo images are much easier because it's intuitive to rotate and align the images occularly/mentally, or whatever is actually happenning. So I think you're on the right track in your last post writing of convincing your brain, or something to that effect. C. __________________________________ Do you Yahoo!? Yahoo! Finance Tax Center - File online. File on time. http://taxes.yahoo.com/filing.html