In article <01bbbb88$07618ac0$eda7b9ce@jerlands.cswnet.com>, jerlands@cswnet.com says...

>I'm interested in achieving 2:1 magnification. Can I accomplish this with
>the Nikkor
>105/2.8 with extension tube or diopter? Do you know of any other lense or
>arrangement more suitable?

You don't say which 105mm f2.8 Nikkor... If it is the AF that focuses
continuously to 1:1, you can use a combination of tubes and Nikon 3T
or 4T achromats (or the Sigma, or other achromat) to get to 2X
magnification with good quality (at f11-16). Using the TC201 is also
a way to do it. Tubes alone may be impractical, since the tube length
may be too great.
Hope This Helps