Borg telescopes are designed and manufactured in Japan. "Borg" comes from a contraction of two Japanese words:

• Bo-enkyo- (telescope)
• Do-gu (equipment)

As far as we can tell, the choice of the name was not influenced by the characters from the Star Trek TV series!

Just a few components for the entry-level Borg line of scopes are plastic. In the past, Borg produced a line of very lightweight, all-plastic entry-level scopes, but currently there are no plastic tube assemblies. All parts for the larger models have always been made of metal (usually a special stiff aluminum alloy), and are precision machined to the tolerances required for high-quality performance.

Unlike the other "traditional" Japanese telescope makers, Borg does not use heavy castings. This results in a comparatively light scope, but this is not due to the use of plastic!

Helical focusers work by turning a ring to focus as we do when using a conventional camera (at least in manual focus mode). A true helical focuser works like a camera -- when you turn the focusing ring, neither the lens nor the camera (or eyepiece and diagonal) rotate. The only motion is in and out. Some manufacturers implement a "pseudo-helical" focuser which results in a rotating camera or eyepiece, but Borg focusers are true helical focusers.

The advantage of helical focusers is the fine adjustment possible, in part due to the fine pitch of the focusing ring's thread, and in part due to the large diameter of the ring. In the case of the Borg helical focusers, virtually backlash-free movement and graduated markings on the focusers allow repeatable return to the focus point simply by noting the focus position reading. The graduation spacings for some Borg focusers are:

• #8167 (large focuser) - 80 microns
• #7857 (M57 focuser) - 100 microns
• #7835 (M focuser) - 80 microns
• #7315 (S focuser) - 50 microns

A complaint sometimes heard about helical focusers is that they have insufficient focus travel. In the case of Borg scope systems, a draw-tube is an option which allows more than enough extra travel to accomodate accessories.

In addition to being a standard component on Borg scopes, a common use for a Borg helical focuser is to add it on to an SCT or any other scope with a coarse focuser such as a rack-and-pinion focuser. Especially in the case of SCT's this allows for fine focus positioning without the annoying image shift which is often large enough to move a target off a small imaging or guiding CCD chip.