ZWO Electronic Automatic Focuser (2025)

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A Precision Upgrade to Your Focus Experience

Hone your focus from your imaging site or remotely and maintain it throughoutthe night with this convenient electronic focuser upgrade from ZWO! Replacingyour manual focus adjustments with the ZWO EAFN system gives you precisioncontrol of your focus and electronic integration that can greatly enhance yourexperience. When connected to a compatible device and software suite the EAFNcan not only be moved by you through the digital focuser interface, but alsoautomatically with today’s incredible autofocus algorithms! Using feedbackfrom your camera, these software systems assess the stars filtering throughyour scope and command the EAFN until your frame is pinpoint sharp. Runningthese powerful focusing features can be as easy as the click of abutton—or even simpler, with modern imaging suites allowing you totoggle EAFN refocusing in response to events which can cause your images todrift out of focus including temperature and filter changes or Meridianflips*. This means you can forget setting timers throughout the night, justset up your system and software with the ZWO EAFN and walk away withconfidence!

Bringing this enhanced level of focus precision and convenience to your systemwith the ZWO EAFN is easy! With the smashing success of ZWO’s EAF design, manyfocusers in use today can natively support this updated model’s similarmounting bracket; allowing many rack-and-pinion, linear bearing, and Crayfordfocuser users to upgrade their experience right out-of-the-box without needingto purchase extra accessories! Sporting an equipment payload limit of 11 lb.even robust imaging systems can be precisely focused with the EAFN’sfine adjustments. Powering and communicating with this excellentelectronic focus companion is achieved with a single connection via the USB-Cport, simplifying cable management. The ZWO EAFN features ZWO’s excellentcompatibility, and is able to be controlled from your ASCOM/INDI compatibleimaging suite of choice or the incredible ASIAir and Air camera lines fromZWO!

*Please Note: Available autofocus algorithms and refocus automation settings vary by software suite and control device. While the ZWO ASIAir and Air camera lines support these features, some imaging suites and WiFi camera control devices may not. Some autofocus algorithms require you are at least rough focused to work properly. Refocusing based on change in temperature requires the ZWO Temperature Sensor (sold separately) or other source of local temperature feedback (for third party software).

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Easy Installation and Extensive Compatibility

Attaching the EAFN to your telescope may seem daunting at first, but no needto fret! The process is simple and straightforward. The EAFN replaces thefocusing knob that rests around the focusing shaft and controls focus throughthis connection. Simply remove this focusing knob and attach the EAF Pro inits stead with the appropriate included coupler. A mounting bracket also comeswith this package to provide support and secures the EAF Pro in its place.There are multiple couplers provided with this EAFN, allowing use with a widerange of telescopes. One side of the coupler attaches to the EAF Pro itself,while the other side fits around the focusing shaft of your telescope. Fourdifferent sizes are provided with this electronic focuser: 4-4mm, 4-5mm,4-6mm, 4-7mm. Unsure if these couplers will fit your telescope? You can easilymeasure the diameter of your focusing shaft by removing the appropriatefocusing knob. Next, take the diameter of the focusing shaft and compare it tothe sizes of the couplers provided to determine compatibility with yourtelescope. This ZWO EAFN is known to work with popular telescope fromSky-Watcher, SharpStar, Apertura, William Optics, and many more! Please referto the manual for more information on compatible telescopes.

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An Easy to Integrate Autofocus Accessory!

Adding the power of computer controlled micro adjustments and autofocusconvenience to your astrophotography system is easy with the ZWO EAFN!

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Easy Integration
Connecting the ZWO EAFN with your imaging command center of choice is easy! For ZWO ASIAir and ZWO Air camera users, the EAFN natively integrates with your WiFi camera control interface for a seamless upgrade to your experience. Users of third party imaging suites can also integrate this electronic focus assistant into their workflows with ASCOM and INDI support available for the ZWO EAFN. For users looking for a more manual, software-free, experience the EAFN features focus In/Out buttons on the device itself in addition to a 3.5 mm jack to allow the ZWO Hand Controller for Electronic Automatic Focuser (EAF)(sold separately) to control focus when on battery power or with an external source of power connected.This versatility ensures that most modern systems can add on this convenient manual focus replacement without any configuration or driver headaches!

Astronomy Hub: Your one-stop-shop for Astrophotography Knowledge!

Our Gear Experts have compiled a wealth of information to help expand your astrophotography knowledge! Below you’ll find links to articles, videos and “how-to” guides. Just one more reason that our Astronomy Hub is a one-stop-shop for all your astronomy and astrophotography needs!