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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
ZWO EAF Temperature Sensor

ZWO EAF Temperature Sensor

by ZWO
SKU ZWO-EAF-Sensor
$9.90 - $9.90
$9.90
$9.90 - $9.90
$9.90
Price Match Policy!
  • Enables temperature-based autofocus compensation for the ZWO EAF
  • Plugs directly into the ZWO Electronic Automatic Focuser
  • Maintains sharp focus as ambient temperature changes
  • Seamless integration with ASIAIR and ZWO imaging software
4 in stock
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • ZWO Temperature Sensor for Electronic Automatic Focuser

    The ZWO EAF Temperature Sensor is the essential accessory for maintaining tack-sharp focus across multi-hour imaging sessions. This single sensor plugs directly into your ZWO EAF, providing real-time temperature data to the control software and is backed by a ZWO 2-Year warranty.

    Automated Focus Compensation for Every 1°C Shift

    As night falls, dropping temperatures cause a telescope's optical tube to contract, shifting the focal point and blurring your images. This sensor measures the ambient temperature, allowing the ZWO ASIAIR or other control software to automatically trigger the EAF and adjust focus based on a pre-plotted temperature curve. You no longer need to manually refocus every 30-60 minutes; the system does it for you, ensuring consistently sharp stars from dusk until dawn.

    Plug-and-Play Integration with the ZWO EAF System

    Designed exclusively for the ZWO Electronic Automatic Focuser (EAF), this temperature sensor offers true plug-and-play operation. It connects to the dedicated port on the EAF body, instantly feeding data into the ZWO ecosystem. The only limitation is its design; it is a first-party accessory engineered specifically for ZWO hardware and is not compatible with other brands of focusers.

    • Seamless Software Control: Once connected, the temperature compensation feature can be enabled with a single click in the ASIAIR app or ZWO's ASIStudio software suite.
    • Set-and-Forget Reliability: There are no batteries or extra controllers required. The sensor draws power directly from the EAF, providing a reliable and maintenance-free solution for thermal focus drift.

  • How does the ZWO EAF Temperature Sensor work?

    The sensor measures the ambient air temperature. As the temperature changes throughout your imaging session, your telescope's metal tube will expand or contract, which slightly changes the focal length. By monitoring this temperature change, the ZWO EAF can be programmed (typically via the ASIAIR) to make small, precise adjustments to the focuser to counteract this thermal drift, keeping your stars perfectly in focus.

    Is the ZWO EAF Temperature Sensor required to use the ZWO EAF?

    No, it is not required, but it is highly recommended for long-exposure astrophotography. Without it, the EAF can perform autofocus routines when you manually trigger them, but it cannot automatically compensate for focus changes caused by falling temperatures over a long imaging session.

    Where should I mount the ZWO EAF Temperature Sensor for best results?

    For the most accurate readings, the sensor should be placed near the main optical tube of your telescope, but not directly touching it, allowing it to measure the ambient air temperature that is causing the tube to change temperature. Many imagers use a small piece of Velcro or tape to attach it to the dovetail bar or finderscope bracket.

    Will this sensor help keep my 11" EdgeHD focused while imaging the Andromeda Galaxy (M31)?

    Yes, absolutely. Large SCTs like an 11" EdgeHD are particularly susceptible to thermal focus shift due to their large metal tubes and mirror systems. When imaging a target like the Andromeda Galaxy (M31) for several hours, the temperature can drop significantly. This sensor allows the EAF to make continuous micro-adjustments, ensuring your data remains sharp from the first sub-exposure to the last.

    Can I use the ZWO EAF Temperature Sensor with a non-ZWO focuser or software?

    No. This sensor is designed with a specific connector and firmware compatibility for the ZWO Electronic Automatic Focuser (EAF). It is intended for use within the ZWO ecosystem, primarily with the ASIAIR or ASIStudio software.

    How do I set up temperature compensation for the ZWO EAF Sensor in the ASIAIR app?

    After connecting the sensor to your EAF and the EAF to your ASIAIR, follow these steps:

    • Navigate to the "AF" (Autofocus) settings page in the ASIAIR app.
    • Enable the "Temperature Compensation" option.
    • The app will prompt you to run an initial autofocus routine to establish a baseline.
    • As you image, the system will track temperature changes and recommend or automatically apply focus adjustments when a set temperature threshold is crossed.
  • SKU ZWO-EAF-SENSOR
    Compatibility ZWO Electronic Automatic Focuser (EAF)
    Function Measures ambient temperature for autofocus compensation
    Warranty ZWO - 2 Years

    • ZWO EAF Temperature Sensor

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  • ZWO 2-Year Warranty