Mooey, you should try to understand a bit more before lambasting people as wrong.
In the case I was pointing out, the adapter IS NOT THICK ENOUGH. Hence the total registration distance is less than 44mm.
Hence, in order to reach focus, the lens must be focused CLOSER THAN INFINITY (i.e. the lens barrel extends forward). This allows the 44mm distance to be achieved without extension tubes.
This would be true of any solution that is "too thin" - focus can be achieved by extending the lens forward, without purchasing additional extension tubes.
Wanna make a scope? Or better still, grind a mirror yourself. Or, you have some good tips in making a really useful accessory? This is the place to show what your hands can do...