ATM Panoptic Barlow Interface

[Carl Woebcke <carlw@telis.org>]

Hello out there,

The Tele Vue web-page
http://www.rahul.net/resource/regular/products/tele-vue-optics/pg11a.htm

says the following about its Panoptic Barlow Interface lens:

"Double the power of Panoptics while retaining eye relief, by adding the
2x Big Barlow and matching interface lens, another first. It pulls the
pupil back to the ideal eyepoint to prevent vignetting, while further
optimizing correction to "Nagler" levels. When using the 2x Big Barlow,
we consider the interface lens essential with the 35mm and 27mm, helpful
with the 22mm, and unnecessary with the 15mm."

I'm thinking of buying the 35mm Panoptic, along with a 2" 2x Barlow and 
a 3x 1.25" Barlow.  Do I need this Panoptic Barlow Interface lens too,
and can I get good 2x, 3x and 6x views with this eyepiece and these
barlows?

Thanks.

Carl Woebcke