ZWO EAF Pro Electronic Automatic Focuser (2025)
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Pre-orders are now live! Secure your place in line by ordering today — initial quantities will be limited!
- Automatically get perfect focus, every time
- Pro model includes focus buttons, battery, and Bluetooth
- 11lb (5kg) capacity for focusing heavy image trains
- Widely compatible with ASIAIR, NINA, ASCOM, & more
- Notice for Celestron SCT & Takahashi users
Perfect Focus Made Easy
The ZWO EAF Pro is an electronic telescope focuser that lets you get perfect focus every time! Featuring a number of upgrades over the previous version like integrated focus in / out buttons, a built-in battery, and a USB-C port, the EAF Pro is an improvement to every astrophotography toolkit.
ZWO EAF Pro Review
Popular astrophotographer The Space Koala shared her thoughts about the new focuser in this ZWO EAF Pro review video:
Three Huge Upgrades for the EAF Pro
Integrated Focus Buttons
The EAF Pro now features dedicated In / Out focus buttons, meaning you can manually focus the EAF Pro! In previous versions, the ZWO EAF had no way to manually focus without an additional hand controller. This added feature is a huge plus to those who want to occasionally use their scope visually or swap out components in their image train. You can still run an automatic focus in your favorite software.
Built-in Battery
In addition to the new buttons, the EAF Pro now also comes with a built-in lithium battery! Previous versions required an external USB power source to run the EAF at all, but now you can run the EAF completely unplugged — perfect for grab and go astronomy or astrophotography. The battery charge will last about one week under normal use before needing to be recharged.
Bluetooth Connectivity
The EAF Pro adds the ability to be controlled completely wirelessly via the ASIAIR app, ASIStudio, and ASCOM software! Featuring a low-power Bluetooth 5.0 chip, you can have one less cable connected to your rig, reducing the possibility of cable snags.
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.
Extensive Software Compatibility
The EAF 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 EAF accomplishes this using a high-precision stepper motor with a 1:128 reduction ratio. This provides the EAF 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 EAF! Start by manually rough-focusing your stars. Then, run an autofocus routine in the ASIAIR app (pictured) or your preferred software. The EAF moves the focuser in and out, measuring star size to generate a V-curve — the lowest point marks perfect focus. The EAF 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 73.4mm
- Weight: 258g
- Payload: 5kg
- Motor Specifications: Stepper motor, step angle 7.5°, reduction ratio 1:128
- Resolution: ≈2.812µm/per step
- Communication Method: USB Type-C/Bluetooth
- Power Supply: USB Type-C (5V 500mA), Built-in Battery
- Battery Capacity: 2500mA
- Temperature Sensor Port: Yes
- Hand Controller Port: Yes
- Power Switch: Yes
- Status Indicator Light: Yes
- Focus Button: Yes
- 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 EAF-N 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 EAF Pro Mechanical Diagram
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
Pre-orders are now live! Secure your place in line by ordering today — initial quantities will be limited!
- Automatically get perfect focus, every time
- Pro model includes focus buttons, battery, and Bluetooth
- 11lb (5kg) capacity for focusing heavy image trains
- Widely compatible with ASIAIR, NINA, ASCOM, & more
- Notice for Celestron SCT & Takahashi users
Perfect Focus Made Easy
The ZWO EAF Pro is an electronic telescope focuser that lets you get perfect focus every time! Featuring a number of upgrades over the previous version like integrated focus in / out buttons, a built-in battery, and a USB-C port, the EAF Pro is an improvement to every astrophotography toolkit.
ZWO EAF Pro Review
Popular astrophotographer The Space Koala shared her thoughts about the new focuser in this ZWO EAF Pro review video:
Three Huge Upgrades for the EAF Pro
Integrated Focus Buttons
The EAF Pro now features dedicated In / Out focus buttons, meaning you can manually focus the EAF Pro! In previous versions, the ZWO EAF had no way to manually focus without an additional hand controller. This added feature is a huge plus to those who want to occasionally use their scope visually or swap out components in their image train. You can still run an automatic focus in your favorite software.
Built-in Battery
In addition to the new buttons, the EAF Pro now also comes with a built-in lithium battery! Previous versions required an external USB power source to run the EAF at all, but now you can run the EAF completely unplugged — perfect for grab and go astronomy or astrophotography. The battery charge will last about one week under normal use before needing to be recharged.
Bluetooth Connectivity
The EAF Pro adds the ability to be controlled completely wirelessly via the ASIAIR app, ASIStudio, and ASCOM software! Featuring a low-power Bluetooth 5.0 chip, you can have one less cable connected to your rig, reducing the possibility of cable snags.
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.
Extensive Software Compatibility
The EAF 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 EAF accomplishes this using a high-precision stepper motor with a 1:128 reduction ratio. This provides the EAF 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 EAF! Start by manually rough-focusing your stars. Then, run an autofocus routine in the ASIAIR app (pictured) or your preferred software. The EAF moves the focuser in and out, measuring star size to generate a V-curve — the lowest point marks perfect focus. The EAF 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 73.4mm
- Weight: 258g
- Payload: 5kg
- Motor Specifications: Stepper motor, step angle 7.5°, reduction ratio 1:128
- Resolution: ≈2.812µm/per step
- Communication Method: USB Type-C/Bluetooth
- Power Supply: USB Type-C (5V 500mA), Built-in Battery
- Battery Capacity: 2500mA
- Temperature Sensor Port: Yes
- Hand Controller Port: Yes
- Power Switch: Yes
- Status Indicator Light: Yes
- Focus Button: Yes
- 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 EAF-N 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 EAF Pro Mechanical Diagram
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
ZWO EAF Pro Electronic Automatic Focuser (2025) # EAF-Pro