ZWO EAFN Electronic Automatic Focuser (2025)
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- Automatically get perfect focus, every time
- Updated USB-C port for seamless connectivity
- 11lb (5kg) capacity for focusing heavy image trains
- Widely compatible with ASIAIR, NINA, ASCOM, & more
- Notice for Celestron SCT & Takahashi users
ZWO EAFN: Perfect Focus Made Easy
ZWO’s most popular electronic focuser has leveled up! The next-generation ZWO EAFN retains its impressive 5kg (11 lb) load capacity while introducing modern enhancements like a USB-C connection — making setup and integration smoother than ever.
Key Specs
- Connections: USB-C, 3.5mm port for temperature sensor or hand controller
- Compatibility: Works with ASIAIR, ASCOM, and INDI platforms
- Load Rating: Supports up to 5 kg (11 lbs) of gear
ZWO EAFN Review
Popular astrophotographer The Space Koala shared her thoughts about the new focuser in this ZWO EAFN review video, which also features the EAF Pro:
Why Choose the ZWO EAF?
Precision, Compatibility, and Power in Every Focus
Heavy Load Capacity
Both EAF models can support a high load capacity of up to 11lbs (5kg), meaning you don't have to worry about dreaded focuser sag. The ZWO EAF can carry all of today's modern astrophotography accessories like the ZWO CAA rotator, a filter wheel, and a deep sky camera with ease.
Upgraded USB-C Port
The EAFN now features a USB-C port, making it easier than ever to connect to your favorite astronomy gear like the ZWO ASIAIR or a computer. A port for the optional temperature sensor and hand controller can be found on the right, which enables more control of the EAFN!
Extensive Software Compatibility
The EAFN works seamlessly with nearly any software on the market, including ZWO's own ASIAIR and ASIStudio, plus ASCOM and INDI based software like NINA, SharpCap, FireCapture, TheSky, FocusMax, and many more.
Micron Level Accuracy
Astrophotography enthusiasts know how critical it is to achieve perfect focus. The ZWO EAFN accomplishes this using a high-precision stepper motor with a 1:128 reduction ratio. This provides the EAFN with strong torque and ultra-precise focusing accuracy, ensuring you get the sharpest image possible, every time!
How the ZWO EAF Works
Achieving perfect focus is easy with the ZWO EAFN! Start by manually rough-focusing your stars. Then, run an autofocus routine in the ASIAIR app (pictured) or your preferred software. The EAFN moves the focuser in and out, measuring star size to generate a V-curve — the lowest point marks perfect focus. The EAFN automatically adjusts to this point and can re-focus after filter changes, meridian flips, or at set intervals to account for temperature shifts.
Specifications
- Dimensions: 41 x 52 x 70.3mm
- Weight: 7.5oz (215g)
- Payload: 11lb (5kg)
- Motor: Stepper motor, step angle 7.5°, reduction ratio 1:128
- Resolution: ≈2.812µm/per step
- Communication: USB Type-C
- Power Supply: USB Type-C (5V 500mA)
- Software: ZWO ASIAIR APP, ZWO ASIStudio; (ASCOM platform and various ASCOM-compatible third-party software)
How to Install the ZWO EAF
Step 1: Remove your telescope's existing coarse focus knob
Step 2: Install the included focuser coupling and tighten the locking screw with the included 2mm hex wrench
Step 3: Attach the EAF to the coupling by aligning the flat surface of the motor shaft with the locking screws on the coupling and tighten using the 2mm hex wrench
Step 4: Secure the EAF body to the bracket and the bracket to the matching mounting holes in the focuser assembly using the supplied M4 screws. Ensure that the bracket is flush with the EAF mounting surface without any gaps, and that it is parallel to the focuser body surface.
Step 5: Check and ensure that all the connections of the EAF are secure. This completes the hardware installation of the EAF.
Step 6 (if necessary): For curved focusers like the one in the image below, you only need to use the original locking screws and 3 washers to secure the EAF. There is a groove at the bottom of the EAF bracket, and a single screw provides sufficient stability.
Notice About EAF Shaft Compatibility for Takahashi & Celestron SCT Users
The new EAF Pro and EAFN units now have a 4mm output shaft and coupling (instead of 5mm in the previous generation). If you are using a special coupling like the ones listed below, you may notice this small change. According to ZWO, while testing shows that using a 5mm coupling with a 4mm shaft still works "within acceptable tolerances" in most cases, it may not be ideal for some users demanding precision.
ZWO will soon begin including an extra 4mm coupling with the following brackets to ensure full compatibility with the updated EAF Pro and EAF-N:
- ZWO EAF Bracket for Takahashi and Some Other Telescopes (EAF-BRK-TK)
- ZWO EAF Bracket for Celestron C8 and C9.25 SCT Telescopes (EAF-C8-C925)
- ZWO EAF Bracket for Celestron C11 and C14 SCT Telescopes (EAF-C11-C14)
These current versions still have the older 5mm coupling, but we will post an update here and on those pages once we have received the newer versions with 4mm couplings.
ZWO will still include the original 5mm coupling with these three brackets too — so you're covered whether you're using the new or older EAF version.
If you need assistance with this or have further questions, please contact us.
ZWO EAFN Mechnical Drawing
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
- Automatically get perfect focus, every time
- Updated USB-C port for seamless connectivity
- 11lb (5kg) capacity for focusing heavy image trains
- Widely compatible with ASIAIR, NINA, ASCOM, & more
- Notice for Celestron SCT & Takahashi users
ZWO EAFN: Perfect Focus Made Easy
ZWO’s most popular electronic focuser has leveled up! The next-generation ZWO EAFN retains its impressive 5kg (11 lb) load capacity while introducing modern enhancements like a USB-C connection — making setup and integration smoother than ever.
Key Specs
- Connections: USB-C, 3.5mm port for temperature sensor or hand controller
- Compatibility: Works with ASIAIR, ASCOM, and INDI platforms
- Load Rating: Supports up to 5 kg (11 lbs) of gear
ZWO EAFN Review
Popular astrophotographer The Space Koala shared her thoughts about the new focuser in this ZWO EAFN review video, which also features the EAF Pro:
Why Choose the ZWO EAF?
Precision, Compatibility, and Power in Every Focus
Heavy Load Capacity
Both EAF models can support a high load capacity of up to 11lbs (5kg), meaning you don't have to worry about dreaded focuser sag. The ZWO EAF can carry all of today's modern astrophotography accessories like the ZWO CAA rotator, a filter wheel, and a deep sky camera with ease.
Upgraded USB-C Port
The EAFN now features a USB-C port, making it easier than ever to connect to your favorite astronomy gear like the ZWO ASIAIR or a computer. A port for the optional temperature sensor and hand controller can be found on the right, which enables more control of the EAFN!
Extensive Software Compatibility
The EAFN works seamlessly with nearly any software on the market, including ZWO's own ASIAIR and ASIStudio, plus ASCOM and INDI based software like NINA, SharpCap, FireCapture, TheSky, FocusMax, and many more.
Micron Level Accuracy
Astrophotography enthusiasts know how critical it is to achieve perfect focus. The ZWO EAFN accomplishes this using a high-precision stepper motor with a 1:128 reduction ratio. This provides the EAFN with strong torque and ultra-precise focusing accuracy, ensuring you get the sharpest image possible, every time!
How the ZWO EAF Works
Achieving perfect focus is easy with the ZWO EAFN! Start by manually rough-focusing your stars. Then, run an autofocus routine in the ASIAIR app (pictured) or your preferred software. The EAFN moves the focuser in and out, measuring star size to generate a V-curve — the lowest point marks perfect focus. The EAFN automatically adjusts to this point and can re-focus after filter changes, meridian flips, or at set intervals to account for temperature shifts.
Specifications
- Dimensions: 41 x 52 x 70.3mm
- Weight: 7.5oz (215g)
- Payload: 11lb (5kg)
- Motor: Stepper motor, step angle 7.5°, reduction ratio 1:128
- Resolution: ≈2.812µm/per step
- Communication: USB Type-C
- Power Supply: USB Type-C (5V 500mA)
- Software: ZWO ASIAIR APP, ZWO ASIStudio; (ASCOM platform and various ASCOM-compatible third-party software)
How to Install the ZWO EAF
Step 1: Remove your telescope's existing coarse focus knob
Step 2: Install the included focuser coupling and tighten the locking screw with the included 2mm hex wrench
Step 3: Attach the EAF to the coupling by aligning the flat surface of the motor shaft with the locking screws on the coupling and tighten using the 2mm hex wrench
Step 4: Secure the EAF body to the bracket and the bracket to the matching mounting holes in the focuser assembly using the supplied M4 screws. Ensure that the bracket is flush with the EAF mounting surface without any gaps, and that it is parallel to the focuser body surface.
Step 5: Check and ensure that all the connections of the EAF are secure. This completes the hardware installation of the EAF.
Step 6 (if necessary): For curved focusers like the one in the image below, you only need to use the original locking screws and 3 washers to secure the EAF. There is a groove at the bottom of the EAF bracket, and a single screw provides sufficient stability.
Notice About EAF Shaft Compatibility for Takahashi & Celestron SCT Users
The new EAF Pro and EAFN units now have a 4mm output shaft and coupling (instead of 5mm in the previous generation). If you are using a special coupling like the ones listed below, you may notice this small change. According to ZWO, while testing shows that using a 5mm coupling with a 4mm shaft still works "within acceptable tolerances" in most cases, it may not be ideal for some users demanding precision.
ZWO will soon begin including an extra 4mm coupling with the following brackets to ensure full compatibility with the updated EAF Pro and EAF-N:
- ZWO EAF Bracket for Takahashi and Some Other Telescopes (EAF-BRK-TK)
- ZWO EAF Bracket for Celestron C8 and C9.25 SCT Telescopes (EAF-C8-C925)
- ZWO EAF Bracket for Celestron C11 and C14 SCT Telescopes (EAF-C11-C14)
These current versions still have the older 5mm coupling, but we will post an update here and on those pages once we have received the newer versions with 4mm couplings.
ZWO will still include the original 5mm coupling with these three brackets too — so you're covered whether you're using the new or older EAF version.
If you need assistance with this or have further questions, please contact us.
ZWO EAFN Mechnical Drawing
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
ZWO EAFN Electronic Automatic Focuser (2025) # EAFN