On Tue, Feb 19, 2013 at 10:58 AM, <erikhansen@thebluezone.net> wrote:
of course the question is how accurately you make your tube assemblies and how good your eye is at determining magnification differences. He also had 4 star diagonals that could also be a source of error. It took a long time to set them up for observing.
A four-star-diagonal system is a kluge and I'm ROFLMAO on that one. Let's assume I build a tight, well-made prism chain with no inherent slop. I'm duplicating a regular binocular arrangement, only using much larger prisms (I already have them). So I'm taking the craftsmanship and design question off the table. We're assuming the Mil spec of 2% maximum magnification difference is good enough since that's what the commercial makers go by. All we are really now talking about is how to make two objectives with focal lengths that are different enough to result in a 2% or greater difference in magnification (the industrial standard). By employing mismatched eyepieces or Barlows, I think we can easily accomplish it. And it just might turn out that my objectives have focal lengths close enough to each other that it's simply not an issue. We'll know more after the focal lengths get measured precisely on Saturday.