The Event Horizon Focuser (EV) is a low-profile, friction-drive focuser designed for both the amateur
and professional market. The highly acclaimed Crayford design (see below) permits tolerances up to 100
times better than conventional rack-and-pinion focusers. Zero image shift and zero backlash makes it
fantastic for visual and photographic work and a must for CCD imaging. The modular design makes
changes and upgrades extremely easy to accomplish. Add the optional variable-speed Motor and Smart
Focus or Digital Readout (DRO) for the ultimate focusing system. The EV is truly a masterpiece of
engineering and workmanship that you will be proud to own for years to come.
A 3” black-anodized (gold-anodized optional) aluminum ”Extreme” focuser designed for use on large (10”
to 16”) Cassegrain Telescopes (NGF-XTc) with standard output threads and Newtonian Telescopes
(NGF-XTn). The Cassegrain version includes a 2” Eyepiece Adapter. The Newtonian version includes a
removable combination base (works on 10” radius up to a flat surface). The manual version of the
NGF-XT lifts up to 8+ pounds and the motorized version up to 18 pounds. Manual ”Nano Drive” control is
approximately 13 times finer than most rack-and-pinion focusers. Regular motorized versions include a
standard hand unit.
The Reverse Crayford Focuser (RCF) is a light-weight, low-profile focuser with a new revolutionary
design - JMI′s low-cost, high-quality answer to plastic focusers. The reverse Crayford design
gives zero image shift and zero backlash. (U.S. Patent No. 6,297,917)
