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ZWO Electronic Automatic Focuser (2025)

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SKU: ZWO-EAFN
$199.00
 
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A Micron-Level Precision Upgrade to Your Focus Experience

Hone your focus from your imaging site or remotely and maintain it throughout the night with this convenient electronic focuser upgrade from ZWO! Replacing your manual focus adjustments with the ZWO EAFN system gives you micron-level control of your focus and electronic integration that can greatly enhance your experience. When connected to a compatible device and software suite the EAFN can not only be moved by you through the digital focuser interface, but also automatically with today's incredible autofocus algorithms! Using feedback from your camera, these software systems assess the stars filtering through your scope and command the EAFN until your frame is pinpoint sharp. Running these powerful focusing features can be as easy as the click of a button—or even simpler, with modern imaging suites allowing you to toggle EAFN refocusing in response to events which can cause your images to drift out of focus including temperature and filter changes or Meridian flips*. This means you can forget setting timers throughout the night, just set up your system and software with the ZWO EAFN and walk away with confidence!

Bringing this enhanced level of focus precision and convenience to your system with the ZWO EAFN is easy! With the smashing success of ZWO's EAF design, many focusers in use today can natively support this updated model's similar mounting bracket; allowing many rack-and-pinion, linear bearing, and Crayford focuser users to upgrade their experience right out-of-the-box without needing to purchase extra accessories! Sporting an equipment payload limit of 11 lb. even robust imaging systems can be precisely focused with the EAFN's micron-level adjustments. Powering and communicating with this excellent electronic focus companion is achieved with a single connection via the USB-C port, simplifying cable management. The ZWO EAFN features ZWO's excellent compatibility, and is able to be controlled from your ASCOM/INDI compatible imaging suite of choice or the incredible ASIAir and Air camera lines from ZWO!

*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).

Easy Installation and Extensive Compatibility

Attaching the EAFN to your telescope may seem daunting at first, but no need to fret! The process is simple and straightforward. The EAFN replaces the focusing knob that rests around the focusing shaft and controls focus through this connection. Simply remove this focusing knob and attach the EAF Pro in its stead with the appropriate included coupler. A mounting bracket also comes with 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 wide range 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. Four different 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 easily measure the diameter of your focusing shaft by removing the appropriate focusing knob. Next, take the diameter of the focusing shaft and compare it to the sizes of the couplers provided to determine compatibility with your telescope. This ZWO EAFN is known to work with popular telescope from Sky-Watcher, SharpStar, Apertura, William Optics, and many more! Please refer to the manual for more information on compatible telescopes.

An Easy to Integrate Autofocus Accessory!

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

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!


ZWO EAF Specifications
Motor: Stepper Motor
Step Angle: 7.5°
Reduction Ratio: 128
Focuser Payload Limit: 11 lbs (5kg)
Supply Voltage: 12V @ 0.5A
Data Interface: USB C
Dimensions: 41 mm x 52 mm x 70.3 mm
Weight: 0.47 lbs (215g)

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!

Measuring Your Telescope For An Electronic Focuser
ZWO ASIAir Ultimate Guide