ZWO EAF Pro Wireless Electronic Automatic Focuser
- 11 lb (5kg) Payload Capacity
- Bluetooth 5.0 and USB-C Connectivity
- Integrated 2500 mAh Rechargeable Battery
- Stepper Motor with 128:1 Gear Ratio
- High Resolution 2.812 μm/step Movement
The ZWO EAF Pro automates critical focus with an 11 lb payload capacity and a stepper motor resolution of 2.812 μm per step, ensuring sharp stars even with heavy imaging trains. Integrated Bluetooth 5.0 and a 2500 mAh battery allow for fully wireless operation, while the entire unit adds only 0.57 lbs (258g) to your telescope.
The EAF Pro’s primary advantage is its ability to operate without a data or power cable. The integrated Bluetooth 5.0 chip pairs directly with the ASIAIR, select ZWO cameras, or a Bluetooth-equipped PC running ASCOM software. This eliminates a common source of cable snags and drag that can affect tracking, creating a cleaner and more reliable imaging setup.
A stepper motor with a 7.5° step angle and a 128:1 reduction ratio produces incredibly fine, repeatable movements of just 2.812 μm per step. This level of precision allows autofocus routines to achieve critical focus that is difficult to match by hand. With a robust 11 lb (5kg) payload capacity, the EAF Pro can drive the focuser on telescopes loaded with heavy cameras, filter wheels, and off-axis guiders without slipping or stalling.
While both focusers deliver automated precision, the EAF Pro is a significant upgrade for imagers seeking a streamlined, cable-free setup.
The ZWO EAF Pro adapts to your specific setup with four distinct control methods. Connect wirelessly via Bluetooth for the cleanest setup with an ASIAIR, or use the USB-C port for a robust, wired connection to a PC with ASCOM or INDI drivers. For manual adjustments at the telescope, built-in buttons allow for quick, software-free focusing, and a 3.5mm jack provides an input for the optional ZWO hand controller.
When paired with software like the ASIAIR and the optional ZWO temperature sensor, the EAF Pro can be configured to automatically refocus when the ambient temperature changes by a set amount. As the telescope's metal tube contracts in the cold, the focal point shifts. The EAF Pro makes the small, precise adjustments needed to counteract this thermal shift, keeping your images sharp all night.
To use the EAF Pro wirelessly, you need a control device with Bluetooth. This can be a ZWO ASIAIR (Plus or Pro), a ZWO camera with an integrated USB hub that can host the EAF, or a computer with a Bluetooth adapter running a compatible ASCOM driver. The internal 2500 mAh battery powers the focuser itself, so no power cable is required for wireless operation.
Yes, the EAF Pro is compatible with most Celestron SCTs, but it requires a specific SCT mounting bracket (sold separately). The standard bracket included with the EAF Pro is designed for Crayford and rack-and-pinion focusers found on refractors and Newtonians. The SCT bracket allows the EAF to securely couple to the SCT's mirror focusing knob.
Absolutely. With an 11 lb (5kg) payload capacity, the EAF Pro is designed for exactly this scenario. A typical deep-sky imaging train with a cooled camera, a large filter wheel, and an off-axis guider is well within its capacity. It provides the torque needed to move the focuser drawtube smoothly without slipping, ensuring the autofocus routine can achieve and maintain sharp stars on bright targets like M42.
The primary differences are power and connectivity. The standard EAF requires a USB cable for both power (5V) and data. The EAF Pro adds an internal 2500 mAh battery and Bluetooth 5.0, allowing it to function completely wirelessly. It also includes physical focus buttons on the body for manual control without a computer.
The internal 2500 mAh battery is charged via the USB-C port. You can connect it to any standard USB power source, such as a computer, a USB wall adapter, or a portable power tank. A full charge can last for several nights of typical imaging, depending on the frequency of autofocus routines.
| SKU Number | ZWO-EAF-PRO |
| Focuser Type | Electronic Focuser |
| Motor | Stepper Motor |
| Step Angle | 7.5° |
| Reduction Ratio | 128:1 |
| Resolution per Step | ~2.812 μm |
| Payload Capacity | 11 lbs (5kg) |
| Data Interface | USB-C, Bluetooth 5.0 |
| Supply Voltage | 12V @ 0.5A (External) |
| Internal Battery | 2500 mAh, Rechargeable |
| Dimensions | 41 mm x 52 mm x 73.4 mm |
| Weight | 0.57 lbs (258g) |
ZWO EAF Pro Body
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