This is a discontinued item.
EV-3r Event Horizon 2" Crayford Focuser - Refractor Telescopes
The JMI Event Horizon EV-3r is a 2" black-anodized aluminum focuser with knurled knobs. The focuser lifts up to 4 pounds. Manual control is over 1½ times finer than most rack-and-pinion focusers.
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 permits tolerances up to 100 times better than conventional rack-and-pinion focusers. Zero image shift and zero backlash makes it superb 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, Smart Focus,or Digital Read Out (DRO) for the ultimate focusing system. The EV is truly a masterpiece of engineering and workmanship.
This Refractor version (EV-3r) mounts on many refractors having one of two different inside diameters of approximately 3.5" and 3.75". The following is a partial list of refractors that should accept the focuser:
Celestron C4-R, C6-R, C6-RGT, Firstscope 102; Orion AstroView 100 EQ / 120ST EQ, SkyView Pro 120; Synta / Sky-Watcher (Pro Computerized) 100ED-EQ5P, 120ED-EQ5P, 120AR-EQ5P, 150AR-EQ5P, (Pro Manual) 102AR-EQ5M, (Pro Refractor OTAs) P80 ED-APO, P100 ED-APO, P120 ED-APO; Vixen ED100Sf
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.
One of the EV focuser modular bases is designed for Cassegrain telescopes. 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 EV Cassegrain focusers achieve focus by moving the eyepiece, camera or other equipment at the back of the telescope instead of the mirror.
Here are a few key features of the Event Horizon focusers:
* Modular design makes purchasing and installing options and upgrades a snap
* Purchase one of our regular models or buy a customized focuser using the Build-Your-Own option
* Low profile with no unsightly springs
* Zero image shift and zero backlash
* Up to eight (8) pounds of lifting power
* Brass clamping rings hold eyepieces and equipment without scratching
* 48mm threads on 1-1/4" adapters
* Your choice of plastic or brass locking screw for different locking characteristics
* Miniature light-weight, high-torque motor the size of an AA battery (motorized version)
* Small slender hand control (motorized version)
* Dual-speed drive with counter (EV-1 model)
* 16 times finer focus than most rack-and-pinion focusers (EV-1 model)
* Available with Digital Readout (DRO) hand control
* Available with Smart Focus for control from your PC (with encoders and positional display)
* Available with PC Focus Control for control from your PC (without encoders or positional display)
* Quality construction and just plain beautiful!