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JMI - Model XT Cassegrain Focuser without Motor

Model#: NGF-XTc

Discontinued Product

Manufactured by: Jims Mobile, Inc. (JMI)

JMI - Model XT Cassegrain Focuser without Motor


JMI - Model NGFXTC  Crayford Focuser w/o Motor (Cassegrain scopes)

The Next Generation Focuser (NGF) is a low-profile, friction-drive focuser designed for both the amateur and professional .  The highly acclaimed Crayford design  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 NGF-XTc is specifically designed for Cassegrain telescopes (10" to 16").  The most popular type of Cassegrain telescope is the Schmidt-Cassegrain Telescope (SCT).  These telescopes achieve focus by moving the primary mirror.  This design tends to create image shift which is especially problematic for CCD imaging.  The NGF-XTc achieves focus by moving the eyepiece, camera or other equipment at the back of the telescope instead of the mirror.

The NGF 3" focusers include a compression ring in the drawtube for holding eyepieces and accessories without scratching the equipment.  The adjusting screw presses against the ring which tightens around the eyepiece or accessory.


Additional Information

Name JMI - Model XT Cassegrain Focuser without Motor
Manufacturer Jims Mobile, Inc. (JMI)
Model NGF-XTc
Discountinued Yes