ATM Barlow Extensions

[jklutts@up.net (James A. Klutts)]

 Hello all!,
             Thanks to Nils, I have also been experimenting with barlow
extensions. The images that I have been able to achieve with my 8in. F/6
have been excellent through 520x. I recently purchased a 2in. barlow for use
with my 2in., 36mm plossl and am going to make tubes for this one also. My
calculations indicate that even at higher magnifications the FOV should be a
little better than with 1.25in. eyepieces. 
 The extension concept is a real plus in that it also provides for easier
viewing than very short focal length eyepieces. I notice no loss of quality
in the images that I'm viewing.
 The calculations in the post from Nils will allow for the calculation of
magnifications for any given length of extension tube.      JIM